Related links:
Calibrating Your Shutters by Andrew Davidhazy R.I.T.
Camera and Lens Testing Tips
Camlogix.com - accurate yet inexpensive Digital Shutter Speed Tester [1/20001]
Camlogix SH-T2 Shutter Speed Tester (online manual..; by Thomas Tomosy)
Denis Pleic's Homebrew Shutter Speed Tester [1/2004]
How to Measure Shutter Speed using a Soundcard for $3
Leica/Rangefinder Adapter [1/2001]
Shutter Speed Tester Options (RIT FAQ#31.6)
The simplest shutter speed tester is a roll of slide film and a sun-lighted subject. Expose the film using the sunny-16 rule (f/16 at 1/ASA rating of the film, e.g., 1/60 for ASA64 slide film at f/16) for bright sunlight (hard shadows). Take a series of exposures of the same subject at different speeds, using aperture off-sets to match (e.g., f16 at 1/60th, f11 at 1/125th, f8 at 1/250th etc.). This simple test will at least tell you if you are in the ball-park with a particular camera and lens. See camera testing page for more testing ideas.
You can also use a record turn-table for testing certain shutter speeds. The turntable will typically make a full 360 degree circle at a speed depending on the type of record chosen (e.g., 33 rpm or 33 rotations per minute). For 33rpm, you would expect 33rpm/60 sec/min = 1/2 rotation per second. Measure the angle moved during the exposure, and estimate the number of degrees turned, and the time that took at 1/2 rotation per second. The result is your measured shutter speed for that setting. Obviously, this trick is handier for slow speed testing than 1/1000th sec! But often these slow speed settings are the first to go on many cameras. Unfortunately, lots of folks don't have record turntables around the house anymore, so the utility of this test depends on your music setup!
Electronic shutter speed testers are easy to build. The first item you need is a simple photo-transistor, such as the FPT-100 series sold for a few dollars at Radio Shack Inc. This device has two leads and a transparent plastic bubble which allows light to shine on the silicon chip. Light turns the device "on", so current or pulses can flow through the device. In the dark, the FPT-100 has a high resistance, so neither pulses nor current can flow through it.
The simplest setup is to use a surplus frequency counter that can be set to count pulses without resetting. Usually, these counters will also have a clock crystal output around 1 megahertz frequency. This output can be fed through the FPT-100 photo-transistor to the input of the counter. You may need to reverse the transistor leads in some setups. Given you have the counter, the cost is very low (under $3 US for FPT-100) and accuracy is very high.
| light
| rays
V
+ ---------------------( - )---------------------- + input counter
FPT-100
1 Megahertz clock out
(from freq counter rear..) [freq. counter]
ground ------------------------------------------------ground on counter
In use, you put the photo-transistor under the lens/shutter you want to test. You shine a bright light on the front of the lens. Reset the counter to zero. Trip the shutter. While the light is shining through the shutter onto the photo-transistor, pulses from the clock output are counted by the counter. When the shutter closes, the photo-transistor turns off as well, so no more pulses can be counted. Simple, huh?
The count on the counter measures how many microseconds the shutter was open. So if a shutter is expected to be 1/1000th second, you would expect a count of 1,000 microsecond pulses for .001 seconds, or 1/1000th second. In practice, you might get a series of readings such as 850 pulses (0.000850 sec), 832, 843 etc. As long as the readings are relatively consistent and close together, the shutter can be used with its actual rather than marked speed in most cases. Lots of shutters will maintain accuracy to within 1 per cent or so (kept at same room temperature etc.).
You can mount the photo-transistor in a
small wood or cardboard jig to hold it against the 35mm camera back while
the back is open for such tests. The photo-transistor clear bubble top
points upward through the back of the camera facing towards the lens and
light source. This way, when the shutter is triggered, light will shine
on and turn on the photo-transistor. The box or mounting jig is pressed
against the film plane, but is setup so as not to interfere with
normal mechanical operation.
I use three layers of cardboard box material, glued together and cut to fit the various camera backs (e.g., 1 by 1.5 inches on 35mm cameras). The pencil eraser sized photo-transistor fits in a hole in the middle of the cardboard mounting jig. The top of the transistor is slightly below the flat surface of the cardboard mount. A similar jig can be used with medium format cameras, especially those which have removable backs. I can just remove the transistor from one jig and insert it into another one in just a few seconds. In all cases, be sure that nothing from the photo-transistor jig will be in the way when the shutter is triggered, or you risk possible camera or shutter damage.
Some cameras won't permit you to mount the photo-transistor jig as needed, as the back may not open up or other problems come into play (e.g., nikonos camera). These cameras may not be tested with this simple setup - sorry 'bout that!
For large format lenses with built-in leaf shutters, it may be convenient to mount the photo-transistor in a small box, with the leads running out the bottom, and the lens simply put on top of the box. Shine a light on the lens/shutter, and trigger the shutter with either the manual or cable release trigger setup.
You can also test cameras with electronic shutters but no shutter setting controls by using a constant light source (daylight, a regulated power supply to a filament bulb, but not fluorescent tubes). Here is a good use for those old neutral density filters you so rarely use! Use the filters to cover up and cut down the light reaching the camera's photosensor. Be aware that if you use colored filters, some meters may react more or less to different colors of light (e.g., blue). In some cameras, you may have to block the eyepiece rear to prevent light coming in the back door, so to speak, and upsetting your readings. As you add filter factors, the electronically controlled shutter should open longer, hopefully directly related to the filter factor. I find this a handy way to determine where the internal light meter runs out of range on cheapy used point and shoot cameras.
You can use this technique in reverse, too, to determine the actual filter factor quite accurately, using an electronically controlled shutter camera. Use a regulated light source of the right color temperature, or a cloudless northern sky (northern hemisphere) during full noon-time daylight. The change in shutter speeds with the filter on the camera should relate directly to the actual filter factor. Again, you may be surprised to discover that actual filter factors vary considerably from what is suggested or marked on them.
What if you don't have a frequency counter to use for this approach? You could spend $70 or so for a Calumet shutter tester that uses a small 9 volt battery and is quite portable. But you might be happier with a simple circuit that uses the common digital voltmeter that most handy-person types have bought from Radio Shack Inc. or other sources for general electrical and electronics troubleshooting.
This electronic voltmeter can be used to do the readout of a simple circuit that charges up a capacitor through your photo-transistor while the switch is open. Once you have made the reading, you have to discharge the capacitor to zero for the next reading. Here is a simple circuit adapted from Thomas Tomosy's Camera Maintenance and Repair Guide (McBroom - editor):
| light
| rays
V
+ ------------( - )------------------------------------+ lead
FPT-100 + | | |
9 volt dc 47 ufd--> U \ reset [DVM]
- | | switch |
- -------------------------------------------------------- - leads
Parts: 47 microfarad 15 volt or higher capacitor (low leakage preferred)
FPT-100 photo-transistor (Radio Shack) or similar
Reset switch - momentary close push-button or similar
9 volt DC battery (or 3 to 13 volt DC regulated power supply)
digital voltmeter, 10 Megaohm input or higher, 1.999 volt scale
The capacitor is a 47 microfarad electrolytic, with polystrene or other high quality low leakage type preferred, oriented so positive lead goes to + 9v side. The switch can be a momentary reset switch (pushbutton) or you can just short the voltmeter leads together in place of a switch. The voltmeter leads are also oriented so plus (red) lead goes to positive side of the 9 volt battery. If your setup doesn't work, try reversing the leads on the photo-transistor.
An alkaline 9 volt DC battery is preferred for portable work, or a regulated bench supply can be used. The battery or power supply isn't critical. It can range from +3 volts up to +13 volts DC (direct current only, not alternating current). None of the parts are critical, so feel free to substitute what you have on hand. Assuming you have a decent digital voltmeter, the entire setup of battery, photo-transistor, capacitor, and switch would cost around $5 from a Radio Shack retail electronics parts outlet.
Use is simple. Plug in the battery (or add a switch to the basic design and put the whole setup into a nice small project case). Put the photo-transistor under the shutter/lens to be tested, generally centered under the lens and pointing up towards the light source. Cock the shutter if needed. Make sure the capacitor is discharged, and the digital voltmeter reads zero. Trigger the shutter. The shutter will open, light hits the phototransistor base, current will flow through the phototransistor, and the capacitor will charge up. How far the capacitor charges up depends on the voltage, circuit resistance, and the size of the capacitor (in microfarads). Read the digital voltmeter value. Usually the 2 volt scale is sufficient up to about 1/30th second, and provides the highest accuracy and greatest range (0 to 1.999 volts).
For slower speeds, you can add a resistor to reduce the rate of current flow into the capacitor. A small 1/4 or 1/2 watt resistor around 10 kiloohms (10k) should do up to about 1 second. An even larger resistor can be used for really long periods of up to 8 seconds or so (100 kiloohms). This resistor simply goes in series with the positive battery voltage lead, before it goes to the FPT-100 photo-transistor. Cost of the resistor is also low (under 25 cents or $0.25 in U.S.). Again, you can substitute widely for these values in your circuit as needed or desired.
Calibration requires an accurate camera, meaning an electronically controlled shutter as in most modern 35mm cameras which is known to be working okay. Simple test the camera shutter/lens as above, noting what digital voltmeter values correspond to which shutter speeds. Do the same for your series resistor setting. If you are using a 9 volt battery, be aware that battery aging will make these results less accurate over time. Either use a fresh battery for your tests, or a regulated AC power supply when more accuracy is needed.
However, we usually aren't concerned so much about accuracy as repeatability. In other words, if a shutter is measured as 1/145th of a second, and it actually is 1/150th of a second, the lack of accuracy in our readout isn't critical. But if this is supposed to be a 1/25th second shutter speed on an old folder, you have an obvious problem. Even worse is if a 1/125th second shutter setting actually varys all over the place, from 1/127th to 1/165th to 1/92th of a second, then the fact that it averages around 1/125th doesn't matter. This shutter speed isn't very reliable, because it is generating a near random distribution of speeds over too wide a range. On slide film, these problems might become quite noticeable.
I also have a view camera lens that has two speeds, bulb (timed exposure) and the same actual 1/120th second speed at each of the 3 usable mid-range speed settings (1/50th, 1/125th, 1/250th). The other speed settings are unreliable and vary hugely. This lens and shutter came free on a used $20 US calumet lens board because of these problems. But I was glad to have it as a startup lens to test out my new view camera. I know which settings I can use, what the real speed is, and I can use a range of apertures and neutral density filters to make this "useless" lens work pretty well. Without a shutter speed tester, the former owner wasted a lot of film and aggravation trying to use this lens, which is how I got it for free. On the other hand, you may find some old folder lens/shutters that are older than your parents which are still remarkably accurate and consistent in speed.
By recording your camera or lens shutter speed settings, you can periodically check out your setup to catch changes and drifting in your speed settings. Using these charts, you can decide that it may be time to get a full camera or lens and shutter servicing.
With the switch to non-mercury alkaline photo-batteries, many folks are discovering that their photo-equipment no longer provides accurate metering or calibration. You can now check your calibration, not only with a fresh battery, but periodically during the battery life-cycle. You can see why many slide film users are upset by one and even two or more stop off-sets when these new, higher voltage batteries are used. See companion battery article for more details and options.
Conversely, you should be able to use a simple, portable shutter speed tester to at least ensure that shutter speeds are in the ball-park, before you buy an expensive camera or lens with shutter. If the speeds are off significantly, or they aren't highly repeatable, then you should beware!
Shutter Speed Testing Booklet
[This booklet may be of interest, presumed available from Mr.
Romney...]
Build a Shutter Speed Tester by Bernard M. Albrecht with an introduction by Ed Romney. A digital Solid State unit that may be either battery or AC powered. It reads Curtain Travel Time as well as Shutter Speed.
rec.photo.misc
From: Ed Romney [email protected]
[1] Shutter Testing Inaccuracies
Date: Thu Mar 26 12:17:23 CST 1998
After I get flamed for presenting honest camera repair data I think the
best thing to do is to present some more valuable camera repair info.
You know...People think a digital readout shutter test is the ultimate
in accuracy. Actually there is a problem that makes many digital
shutter tests read low. It is most severe at high shutter speeds with
leaf shutters such as Copal, Prontor or Compur. If the shutter tester
is set so sensitive that it records the moment the shutter blades crack
open, your reading will be greatly inaccurate. A 1/500 sec leaf shutter
in perfect repair will read around 1/300 sec for the total time it is
open since there is a rise time while the blades open and a decay time
when they are shutting. The 1/500 sec is the average time, or the area
under the curve. You must set the tester carefully so it begins it
digital count when the blades are half open. This is done by adjusting
the intensity of the light or the sensitivity of the photocell or by
placing a narrow angle sensor at the point the blades are half open. If
your shutter test indicates only the higher speeds are slow, you must
question whether the tester is set correctly. The problem also exists
with focal plane shutters, but the error is much less.
Long long ago when I fixed radio and TV sets and taught repair of them at Mass Radio School, we had vacuum tube tube testers that read "good" or "bad" on a big meter. A dishonest TV repair shop could make any radio tube test bad by setting its filament voltage too low...The same could easily be done with a digital shutter tester to sell an unnecessary cleaning, lubrication and adjustment , CLA job. It would be done by making the light too bright or the cell sensitivity too great. If you like this data, guys, please say so..if not, I'll cut it out, I dont like spam any better than you do..Best wishes..Ed Romney
From: [email protected]
Newsgroups: rec.photo.equipment.large-format
Subject: Re: shuttertesting (was:Re: old shutter accuracy)
Date: Mon, 06 Apr 1998
Do you know a chaeper method of testing if a shutter have the right
timing ???
Photograph a television set (preferably a B&W image). The TV screen is
build up of lines. Get some information about the number and velocity
of these lines at your local librairy or TV-repair-shop, and just
count the lines in your photographs. It's a lot of work, but it's very
accurate, and it costs exactly $ 0,00.
Good luck
Gilbert Dumont
From: [email protected] (Richard Knoppow)
Newsgroups: rec.photo.equipment.large-format
Subject: Re: Shutter Time Testing
Date: Sun, 19 Apr 1998
Matthew Harrington [email protected] wrote:
>Dose any one have any experience with these items I noticed Calumet has
>one in their catalog. What do some of you use to check all those
>shutters we all have
>
I'll add to the crowd. I've had a Calumet tester for several years
and its invaluable. Even if your shutters are old and don't perform
as marked any more (many never did anyway) you can determine the
actual shutter speed and also whether the shutter is consistent.
There is a technique for getting accurate measurements of
focal-plane shutters in the instruction book and it works. You can
test large shutters (Speed Graphic) or 35mm shutters and find out if
the speed is varying across the film as well as the speed.
The indicated speeds for higher shutter speeds will be lower than
the markings due to the fact that the meter measures the open time of
the center of the shutter rather than the equivalent time which is
what the calibrations indicate. Shutters are calibrated for
equivalent exposure time at maximum opening. Since the shutter takes
a finite time to open and close it is partially closed during part of
the time. For that reason, for instance, modern Compur shutters will
measure around 1/375th when set at 1/500th. That is because the meter
is measuring the time the center of the shutter is open. It _is_ the
actual effective time for small stops.
My Calumet meter also seems to give accurate readings for the
duration of strobe flash. That can be useful in determining whether a
recoprocity failure correction needs to made.
This meter has gone up in price since I bought mine but is still
IMHO a bargain.
---
Richard Knoppow
Los Angeles, Ca.
[email protected]
From: Gary Hunt [email protected]
Newsgroups: rec.photo.equipment.large-format
Subject: Re: Shutter Time Testing
Date: Tue, 28 Apr 1998
Jean-Christophe Barnoud wrote:
> I have been interested in trying the oscilloscope approach for some > time but have been stopped by the difficulty of finding / building the > light probe / sensor. What can one use ?
If you have an oscilloscope you can use almost any light-sensitive electronic device (e.g. phototransistor, photodiode, even a silicon photocell) for measuring ordinary shutter speeds (although probably not electronic flash durations--some may not be fast enough.) Radio Shack sells a matched infrared emitter and phototransistor detector for about $2 in their catalog that would probably do nicely. You will have to be a little careful about aligning the light source, shutter and detector; and be aware that with leaf-type shutters like those used in large-format lenses, the time you will measure will usually be longer than the 'effective' shutter speed for the smaller f-stop settings commonly used with these lenses.
From: Randolph Carlisle [email protected]
Subject: Response to Help evaluating Zeiss 6x9 folder
Date: 1998-04-28
The stiffness when setting the 1/400 (or the shutter's highest speed is
normal and has been a feature of every Compur shutter I have had. You may
wish to have the shutter cleaned but do not expect much acuracy from the
older Compurs.
It is only important that you know what speed it is giving. You can buy
your own shutter speed tester from Calumet. I paid $65 for mine but it
has been some time ago. Many of the old, worn, Compurs give 1/125 for
everything over 1/60! If you have the shutter cleaned by a repair shop,
they will probably be able to test it for you.
From: Jean-David Beyer [email protected]
Newsgroups: rec.photo.equipment.large-format
Subject: Re: Shutter Time Testing
Date: Fri, 01 May 1998
Sebastian Laiblin wrote: > [email protected] (RWatson767) wrote: > > >Sebastian > > Re sound clicks. I don't think you ears will be able to discerne the time > >between clicks. > > no ... not hearing the clicks with your ears, but looking the oszilloscope-like > view of your audio-programm (ie. cool edit -> you could measure times from > 3/10000 or so ...) and measure the time between the clicks ... > > Sebastian
You might have trouble with clicks, even with an oscilloscope, since the
blades start to move before there is any shutter opening, and close before
they come to a stop in order to increase the shutter efficiency. Thus,
even if the click at each end of the exposure were clearly defined (not
always the case), it would give only an upper bound on the exposure time.
Even if you use a photocell and light source to drive the oscilloscope (a
much better procedure), you must not drive the photocell too hard or allow
any clipping to occur in the oscilloscope's vertical amplifier or your
shutter will appear more efficient than it really is and you will measure
the area under the curve incorrectly, giving incorrect effective shutter
opening times.
--
Jean-David Beyer
Shrewsbury, New Jersey
rec.photo.equipment.large-format
From: [email protected] (Richard Knoppow)
[1] Re: Shutter Time Testing
Date: Tue May 12 03:49:48 CDT 1998
>How much is such a >shutter-tester, is it powered >by battery?
If you mean the Calumet tester its about $80US now. I don't know
who sells it in Germany. It runs on a single nine-volt battery. It
takes some understanding to understand what it is measuring. At slower
speeds it is very accurate but for shutters with considerable opening
and closing times it will read slower than the effective shutter
speed. It also takes a special technique to measure focal plane
shutters. The instruction book covers that. It is a very handy tool
to find out what your shutters are really doing and how consistant
they are. It doesn't matter so much if the speeds of an old shutter
no longer match those marked on it as long as you know what the actual
speed is and know that it is the same speed each time.
Its about the size of an exposure meter and weighs very little.
---
Richard Knoppow
Los Angeles, Ca.
[email protected]
From: "Nicholas F. Hanks" [email protected]
Newsgroups: rec.photo.equipment.large-format
Subject: Re: old shutter accuracy
Date: Sun, 29 Mar 1998
Steven -
First thing you do is get the Calumet shutter tester at around $70. I use
mine regularly. What I have gleened from having several supermatics and
Ilex's CLA'd recently is that each speed has a cam and there are no
intermediate settings. The high speeds are always off even after cleaning
and 1 second is usuually around 3/4 second. Both Steve Grimes and Paul
Ebel have been mentioned on this board as individuals that do this kind of
work. Steve also made me a very nice knurled retaing right for my 100 WF
ektar so that it mounts right to a #1 board.
Of course then there's the problem of 1/25, 1/50, 1/100.... instead of the
current 1/30, 1/60, 1/125 that my meter uses.
Good Luck, Nick
Date: Fri, 21 Aug 1998
From: David Foy [email protected]
To: [email protected]
Subject: RE: [Rollei] Mearsured Shutter speeds
Further thoughts as a result of this most
interesting post (and Tony Zocolillo's informative
reply)...
The speed of a leaf shutter isn't the simplest
thing to measure. Consider that it is in
transition from fully closed to open, and then
back to fully closed, for some considerable
fraction of the total exposure, especially at high
speeds. During those times there is light being
passed at some value that varies from zero to full
intensity. Exposure takes place at full intensity
only when the shutter is fully open. It's taking
place at lower intensities during the opening and
closing phase. The expensive speed-testers used by
repair shops allow the tech to account for this --
the kinds of testers we amateurs rig up don't, so
we need to think a little about our results.
If your detector was a photodiode or
phototransistor, and your light source was a
fairly small penlight, your setup measured what
amounts to a point source at the centre of the
lens, so it's a somewhat rough approximation of
what actually exposes film. A diffuse light source
at known intensity measured by a diode array or a
sensor with a larger surface would probably give
different times, probably somewhat longer at the
top two speeds.
At 1/500 the shutter is, as Tony noted, actuated
by a secondary kicker spring which flicks it open
and immediately flicks it closed (that's why you
get that extra tension when setting the shutter to
1/500 -- you're cocking a spring). Travel time is
very significant. At 1/250 the kicker spring is
out of the circuit and the shutter's main spring
does the same thing, opening and closing the
shutter immediately. Travel time is once again a
significant fraction of the total. At the slower
speeds, a clockwork is switched in which delays
the closing action briefly. Travel time is
probably insignificant from 1/125 on down.
Your results show pretty good progression from one
speed to the next, with the slow speeds, 1 second
to 1/15 giving you something acceptably close to
the doubling one expects. They are, as you note,
about half as fast as they should be, a
consequence, probably, of clockworks inhibited by
fouling. The 1/30 and 1/60 speeds are actuating
more or less normally, and are probably not
affected by inaccurate measurement of travel time.
From what I remember of the last time I cleaned a
Rolleicord, it's very likely the fouled gear teeth
aren't in the circuit at the speeds above 1/60.
From 1/125 up, the action is probably being slowed
by fouling on the blade rotators, if not on the
blades themselves, and more accurate measurements
would probably reveal that travel times have the
effect of making them even slower than what you
found.
should be:
> 1/500 = 4ms 2ms
> 1/250 = 7ms 4ms
> 1/125 = 11ms 8ms
> 1/60 = 16ms 16ms
> 1/30 = 35ms 33ms
> 1/15 = 120ms 66ms
> 1/8 = 275ms 125ms
> 1/4 = 500ms 250ms
> 1/2 = 1s 500ms
> 1 = 2s 1s
I find this kind of thing fascinating. Many thanks
for the contribution.
David Foy
MarkeTactics(TM)
PO Box 52300
Calgary, AB T2M 8K9
Canada
(403)282-0512, voice and fax
Date: Sat, 22 Aug 1998
From: Richard Knoppow [email protected]
To: [email protected]
Subject: Re: [Rollei] Mearsured Shutter speeds
Anything which causes drag in the shutter will slow it up. The slow
speeds are controlled by a clockwork regulator which is slowed down by
gummy lubricant. The highest speeds are controlled mainly by the friction
in the mechanism. Dirt, gummed lubricant or weakened springs will slow it
down. Usually a thorough cleaning will bring the shutter back on speed.
The highest couple of speeds will always read a bit low when the total
open time at the center of the lens is measured. The opening and closing
time is finite. For the shutters used in Rolleis it is about 1/1000 second.
The shutters are calibrated at the highest speeds for the _equivalent_
shutter speed with the lens wide open. That will be about 20% slower than
the marked speed. e.g. 1/500 should measure around 1/400 when measured this
way. Your speeds indicate that the shutter is dirty.
It is also possible in many Compur shutters to adjust the low speeds by
shifting the retarder a little. Generally this is set to make 1/10 sec and
1/sec right. The other speeds will fall in provided that no one has gotten
into the shutter and bent stuff to try to adjust it.
----
Richard Knoppow
Los Angeles,Ca.
[email protected]
Date: Sat, 22 Aug 1998
From: Richard Knoppow [email protected]
To: [email protected]
Subject: Re: [Rollei] Mearsured Shutter speeds
Older Compur shutters have the booster spring. From the speeds indicated
as marked on the shutter this is a Synchro-Compur which has only one
spring. Its the same spring used to drive the Hasselblad shutter which is
meant to be left cocked. It is under considerable tension when installed so
these shutters can be left cocked without damaging the main spring. They
should probably still be changed when the shutter is serviced. Onec th
shuter is opened up these springs are not hard to change.
The booster in the older Compur is why the speed should not be changed to
1/500 when its cocked. The spring is compressed by a boss on the speed cam
and it can get under the cam and jam the shutter beside putting a lot of
strain on the spring and cam. On the Synchro-Compur the speeds can be
changed at will regardless of whether its cocked or not.
----
Richard Knoppow
Los Angeles,Ca.
[email protected]
Date: Sat, 22 Aug 1998
From: Richard Knoppow [email protected]
To: [email protected]
Subject: Re: [Rollei] Rollei TLR Shutters
you wrote:
>Thanks for the post about the shutters, Richard Knoppow. > > So the Synchro-Compur shutter on my TLR 2.8 D can >be moved to 1/500 of a second after it is cocked? I >was under the impression that it could not. It does >say Synchro-Compur on the front of the camera. > > Thanks, > > Rich Lahrson > [email protected]
Yes, but a correction is in order. Deckel made two quite different
shutters under the name Synchro-Compur, both of which are used on Rolleis.
The earlier shutter has a booster spring and should _not_ be set after its
cocked. These shutters have the old series of speeds 1, 1/2, 1/5, 1/10,
etc. The later shutter, as used on the 2.8D is the type which can be
changed while cocked, it has the later speed series, 1, 1/2, 1/4, 1/8,
1/15, etc.
----
Richard Knoppow
Los Angeles,Ca.
[email protected]
Date: Sun, 23 Aug 1998
From: Richard Urmonas [email protected]
To: [email protected]
Subject: Re: [Rollei] Mearsured Shutter speeds
> Method: Photo detector connected to on digital oscope. The detector > was placed in front of the taking lens. Pen light through the back. > Aperture 2.8. Set the oscope to trigger on the shutter. I took 5 > measurements at each speed and avg. (rounded) > Results: > 1/500 = 4ms > 1/250 = 7ms > 1/125 = 11ms > 1/60 = 16ms > 1/30 = 35ms > 1/15 = 120ms > 1/8 = 275ms > 1/4 = 500ms > 1/2 = 1s > 1 = 2s > > Question: I was under the impression that the shutter was only effected > by slow speeds. Looking at the data. Clearly, the upper speeds can be > effected, or is there something wrong with the camera.
As mentioned by someone else the error at the fast speeds is due to the
allowance for the shutter opening and closing times. Notice that they are
about 3ms longer than required. This seems a fair allowance for opening
and closing times using your measurement method.
The slower shutter speeds on a Compur-Rapid shutter (older Rollei's) and
I guess the newer Compur series are controlled by a single escapement
mechanism. This involves a cam which holds the shutter in the open
position. The escapement slows the rotation of the cam. When you cock
the shutter the position of the cam is set by the shutter speed required.
Hmmm the above doesn't sound too clear. Let me restate this. When you
cock the shutter a cam swings out to a position based on the shutter speed
setting. When you release the shutter it catches the cam. The cam is slowly
pushed out of the way. The cam rotates at a constant speed due to the
escapement. So the further out the cam was set the longer the exposure.
When the shutter timings are out it is generally due to one of two
reasons; the escapement is gummed up ;or the shutter blades are gummed up.
Typically if the shutter blades are gummed so is the escapement.
The sympoms your measurements describe are due to a gummed up escapement.
At 1/125 the cam only just clips the shutter mechanism and so the error
is not obvious. At slower speeds the slow operation of the escapement
is more obvious. As the escapement operates at a constant speed the
slow shutter speeds will remain in the correct relationship. Your
camera just happens to be close to 1/2 speed ! (so your one stop error).
BTW gummed shutter blades can be seen when the blades open in "slow motion"
and are usually due to some idiot who has decided to fix their own camera
rather than having it done professionally. Oh well I have aquired several
Rolleis at bargain prices with gummed shutter blades.
Richard Urmonas
[email protected]
From: [email protected] (Gordon Pritchard)
Newsgroups: rec.photo.equipment.misc
Subject: Shutter-Speed Tester - Built, now some Q's and thoughts
Date: Mon, 30 Nov 1998
Hi, All:
I built the shutter-tester outlined on:
http://www.geocities.com/Yosemite/2131/shspeed.html
It worked - Cool!! Being in the electronics business, I
used an oscilloscope instead of the computer/soundcard/software
that was suggested.
I have some Questions, and some Observations:
Questions:
==========
1) When I measure shutter speeds up to about 1/60s, I get
readings that are "right on". At higher speeds, I get
shorter readings... (like, I see 1/100s at 1/125 on my
2-year-old K-1000). Is there an expected "rule" that
higher shutter-speeds are generally off by a bit? Higher
speeds got worse (like, 1/1000s reads 1/600s)...
2) Has anyone else built this circuit? What are your thoughts
and observations?
Observations:
============
1) Using fluorescent lighting sucks :-( I wound up using
a flashlight for ripple-free and bright lighting. I got
_much_ crisper waveforms than the authour's pictures.
2) I couldn't get a BPW40 phototransistor (Vancouver, BC
Canada), but I could get a Siemens BP103. It works fine;
probably _any_ photo-sensitive device will work! The BP103
phototransistor has a base connection, which I left un-
connected.
3) For monitoring with an oscilloscope, I connected the
transistor's emitter straight to the resistor (basically
bypassing the mic-connector and the switch). I got my
waveforms by monitoring across the resistor.
4) When I tried this tester on a leaf-shutter camera with
fixed lens (Minolta 'A', Olympus Trip 35), I found that
the lens (due to focussing of the light) made placement
of the phototransistor critical. Putting the transistor
behind the film-plane eased this...
5) On an SLR, easiest results were obtained with the lens
removed (K-1000).
6) With my nearly-dead 2-cell flashlight, I got waveforms
with a peak of just over 1V. Rise and fall times were
in the neighbourhood of 500us, and looked much "straighter"
than the Web-page pics.
Overall, it was a cool little project. I just soldered onto
the 'AA' battery, and used the component leads themselves as
wires. It took about 5 minutes to build and try it out. Now,
I've gotta clean it up, maybe even incorporate an LED
light-source in a little plastic box.
-Gord
Gordon Pritchard, VE7AGW
White Rock, B.C. Canada
[email protected]
[Ed. note: from some recovered crashed email files...]
Date: Mon, 26 Jul 1999
From: Jerry Flanders [email protected]
To: [email protected]
Subject: Sound Card shutter speed tester
Add this to your web page on shutter speed testing if you wish:
I built the shutter speed testing circuit described on the web page
http://www.geocities.com/Yosemite/2131/shspeed.html
and discovered it was difficult to measure high shutter speeds (higher
than about 1/100 second), probably because of the time constants of the
isolation capacitors inside the sound card. Apparently, the time to charge
and discharge this capacitor is so long that it obscures the moment the
shutter closes for high shutter speeds.
This effect is shown on the example Cooledit96 1/125 second example graph
on the web page where the initial charge event has not finished before the
start of the shutter closure, making it difficult to interpret just where
the closure takes place. It is even more difficult to measure faster
speeds, where the change from shutter open to shutter closed occurs even
sooner, before the voltage has stabilized on the sound card.
To get around this difficulty, I have modified my circuit slightly and
find CoolEdit96 now gives me data that is very easy to interpret, even at
1/1000 second shutter speed.
I have the phototransistor in series with a 4K resistor and 1.5 volt cell,
and take the output from across the 4k resistor. I run this output signal
through a 3900 pF capacitor to the mike input of the sound card. the
resulting voltage spikes that occur when the shutter opens
(negative-going) and then closes (positive-going) are now so quick and
widely separated and it is easy to pinpoint the exact times of each event
(more like the 2 second example graph the referenced web page shows).
I am also using a point light source (a laser pointer) and made a cover
with a pinhole for the phototransistor to minimise any inaccuracy from
extended light source effects. I don't know to what extent this is helpful
- it is just how I have it set up.
Also, using the "Samples" option for the "VIEW - Display Time Format"
toolbar setting in CoolEdit96 will allow a much higher time readout
resolution than milliseconds decimal time.
I have only measured speeds of a focal plane shutter, and don't know how
well this rig would work with a conventional leaf shutter.
I was surprised that a very old Nikkormat FTN mechanical shutter was still
pretty accurate:
Scnds Mrkd Measured %Error 1 1 0.958188 4.18125 0.5 2 0.479729 4.054167 0.25 4 0.251146 0.45833 0.125 8 0.126625 1.3 0.067 15 0.063938 4.570896 0.0333 30 0.033625 0.97598 0.0167 60 0.016375 1.946108 0.008 125 0.010104 26.3021 0.004 250 0.003917 2.083333 0.002 500 0.002188 9.375 0.001 1000 0.001042 4.16667
Only the 1/125 speed is significantly off on the old Nikkormat.
I didn't round off the data because I am lazy, but it is certainly not
good to the several decimal places shown here.
Jerry Flanders, W4UK
From Rollei Mailing List;
Date: Wed, 01 Sep 1999
From: Richard Knoppow [email protected]
Subject: Re: [Rollei] Rollei Users list digest V5 #16
you wrote:
>even 1/500 is utopic. i never saw a mechanical shutter to score 1/500. my best >one was timed at 1/425 > >andre
The marked shutter speeds are the "effective" speeds with the lens wide
open. Since the shutter has finite opening and closing times it is
partially closed during the time of exposure. The logic is that at the
highest speeds the aperture will be wide open or near it.
The actual opening and closing times for a small Compur shutter are
around 1/2000 each way. If you measure the total open time, the time the
center of the shutter is open, the time for a Synchro-Compure or
Compur-Rapid will be around 1/400 or a bit more at 1/500
Focal Plane shutters also have longer effective times than the marked
speeds due to diffraction at the edges of the slit. The error is related
to slit width, distance of the curtain from the focal plane, aperture
setting, and focal length. Not much of a problem with small cameras but
quite significant for larger FP shutters such as those on Speed Graphic
and Graflex cameras.
----
Richard Knoppow
Los Angeles,Ca.
[email protected]
From Hasselblad Mailing List:
Date: Wed, 23 Aug 2000
From: [email protected]
Subject: Re: 35 vs MF, was: Serial numbers
[email protected] writes:
A lens with a built in shutter that goes to 1/1000 of a second!
Mark William Rabiner
How about a lens with a built-in shutter that goes to 1/500, that
*actually goes* to 1/500? I've yet to check one that really goes that
fast. Most are 1/3-1/2 stop slow at best. Kodak used to have a lens
shutter (I think it was either in one of their 620 folders or the
Medalist) that claimed 1/800 but it too was way optimistic. I think
Hasselblad gives us the best solution with very *workable*
focal-plane/leaf shutter bodies/lenses. If you've ever used a Pentax 67
with one of the LS lenses (actually the 90 was discontinued long ago, only
the 150 remains) you know what I mean.
Date: Sun, 08 Oct 2000
From: Michael Briggs [email protected]
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: A mechanical shutter speed accuracy question
Henry Forson wrote:
> How much error in a mechanical shutter's speed > is considered normal? I'm looking for a little > perspective from those with more experience in > such matters.
The brochure that came with a Copal Press #1 (mechanical) shutter that I
have specifies +/-30% accuracy on all speeds. Measurements that I have
made on several Copal shutters and one Compur with a Calumet shutter
tester show that they are sometimes off by this much but that typical
errors are quite small, roughly 1/6 stop.
> The shutter on my Mamiya C-330 135 mm TLR lens > seems to be anywhere from 1/10 to 2 stops slow. > The 2 stops error is at the 1/8 second setting -- > it's close to 1/2 second.
This is clearly wrong and should be fixable by a competent repair
person.
> One local repair person listened to the lens, said > everything sounded smooth, and figured that it was > as good as they get.
Did he just listen? He should have measured the speeds.
> He's probably right, but > somehow, perhaps from the Internet, I got the > impression that mechanical shutter speed accuracies > should be on the order of +/- 1/3 stop.
You are correct.
> Hmmm, this > reminds me of a long thread about 1/10 stop readings > on light meters ...
If anyone suggests that two-stop errors are acceptable, it is just as
absurd as the more common idea that 1/10 accuracy is possible.
--Michael
Date: Sat, 23 Dec 2000
From: Russ & Kathy Thornton [email protected]
Subject: Re: checking compur shutter speeds
I also use a counter. I bought mine in a government auction. It is a
Racal Dana brand and dose a fine job if interval timing. Some of the
technical types may find this amusing but I use a simple, modern photo
cell. It has one disadvantage and that is it does not work very well on
linear type shutters like those found in 35 mm cameras at speeds beyond
the flash sync speed. I have not been concerned with any of those yet.
What I have found, though, is that one of my older Hassy lenses has some
speeds that are a full stop off. The 1/500 is only 1/320 for instance.
What I do is make a custom label that goes in the front barrel of the lens
with the corrected speeds on it. Then when I use my handheld meter I use
the closest meter setting to the corrected speed.
It works in my mind at least.
Russ
From Hasselblad Mailing List;
Date: Thu, 21 Dec 2000
From: Colin Howarth [email protected]
Subject: Re: checking compur shutter speeds
Michael Buchstaller [email protected] wrote:
>Hello Colin, > >>I'm designing a little electronics gadget to measure the shutter >>timings. > >Very interesting. Two years ago, i wanted to do the same thing: >You would put the camera in front of a bright light source and a photo >diode behind the shutter. When light begins to come through, a counter >is reset and then started (clocked with 100 KHz), and stopped when >there is no light; the counter value displayed by 7-segment LED's.
Funnily enough, this is more or less how I want to do it, except I'm using
an IR photo diode and an IR source. Also, since I'm using the
microcontroller counter and 8 Mhz crystal I'll have resolution of 125 ns
:-) (might need a bit of autoscaling)
>I did not want to build do much counter stages, so i decided that this >would be a good job for an embedded processor, expecially when >considering that a protograper would prefer to read "1/250 sec + 15%" >instead of "4.094 mS".
Yep. Embedded processor is the way to do anything (except take photos)
>I started out with an 68HC11 ... >Just recently i have gotten in contact with another MPU, the Atmel AVR. >This is much better than the HC11, it is easy to come by, cheaper and >has 8 KB on Flash ROM; enough for such a project.
How strange, I'm also using an Atmel. :-) The AT90S2333 has an ADC, an
analogue comparator, 16 bit counter and I've already written an LCD driver
for it.
>Your post has remembered me to finish this project.
The race is on.
>>Does anyone know how long it takes the shutter to go from fully closed >>to fully open? >>(presumably this is the same time as takes to go back to fully closed >>again). > >When i thought about this subject, i was assuming that the shutter opening >speed would be roughly the same as the closing speed; thus the time >delay would be negligible. >The only thing would be to adjust a threshold value that matches the light >source used and gives consistent results.
I just looked at Ansel Adams' The Camera. From his diagrams he assumes
that the amount of light passing the shutter varies linearly with time and
takes about 1.5 ms to open 100%. He also talks about "efficiency" which is
the actual amount of light passing divided by the amount which would pass
if the shutter opened and closed instantaneously.
Anyway, if one assumes an approximately linear rise in light intensity
then one could meassure the *effective aperture speed* by starting and
stopping at 50% of the maximum intensity.
I plan to measure the initial maximum intensity (shutter fully open) and
then adjust the Vref for the analogue comparator to, e.g. 50%.
Actually, since the ADC will do up to 15 kSPS (i.e. 30 samples in 1/500 s)
I might try and see what's really happening.
>Please feel free to further discussion about this subject. I am writing directly >and not to the group because i consider in-depth technical talk about it to >be too far off-topic.
I don't think this is off-topic is it? If so, apologies.
I'd still like to know what are considered acceptable errors on Zeiss
Compur lenses.
colin
From ROllei Mailing List:
Date: Thu, 28 Dec 2000
From: imagineero [email protected]
Subject: [Rollei] shutter testing page found!
For any out there with a basic understanding of electronics it is possible
to test the shutter yourself. For me this is useful as I want to
calibrate the shutter speeds myself. It is possible for a user to adjust
the shutter speeds on a flex, there are 3 adjustments to be made, though 2
of them involve bending parts and are not for the weak of heart! The slow
speed escapement can be adjusted fairly easily with a minimum of shutter
disassembly though and may be worthwhile; you can clean the shutter parts
while you are at it!
The page is at;
http://24.0.232.44/cunningham/Tech/Shutter/ShutterTest.html
It's not the same page I read a year or so ago, but explains the process
fairly well anyway. WIll get back to you with details on how my shutter
adjustment went and possibly some pics and a webpage in about 2 weeks.
Shaun
South Korea
P.S. Thanks to those who posted URL's for the camera supplies stores -
much appreciated!
From Leica Mailing List:
Date: Tue, 17 Apr 2001
From: "Austin Franklin" [email protected]
Subject: RE: [Leica] RE: Was Medium format camera (now pit-bull arena)
> >I'd be curious if you happen to have the acceleration curves and/or the > >open/close times for any leaf shutters? That would certainly > substantiate > >or refute the claim that it doesn't matter. My understanding that this > >phenomenon does matter is apparently standard knowledge, and has been > >discussed extensively on the Rollei and LF lists. > > Austin > > ALL mechanical shutters haver errors. It goes with the turf. But the > errors in mechanical shutters, or, at least, the better ones, are within > the permissible window the film will allow. If your shutter is off 1/6 > stop, it doesn't matter, so long as the film will allow a 1/3 stop window. > > Marc
For the most part, I agree, and accuracy is obviously more important
depending on what film choice you make.
This is second hand information:
The opening and closing of medium size late version Compur shutters
takes about 1/1000 second total. For a #1 Compur the factory adjustment is
to have a total open time at 1/500th of about 1/380th second.
For shutters like the Compur Rapid, as found on Rollei cameras, the loss
is around 20% to 50%, perhaps 1/3rd stop to 2/3rd stop at most. The
effective speed for small stops for the Compur shutters used on Rolleis is
around 1/380th for the speed marked 1/500th, providing the shutter is in
good condition.
To: [email protected]
From: [email protected]
Date: Fri, 7 Dec 2001
Subject: Re: [camera-fix] Home built shutter speed tester
On 6 Dec, Kenith Ryan wrote:
> Hi. Just joined the group earlier this week and have been going
> through the archives, where I found this link.
>
> http://www.geocities.com/Yosemite/2131/shspeed.html
>
> It tells how to build a shutter speed tester. I thought this was great
> and went to the local Radio shack to get the parts. Unfortunately,
> they did not have what I needed. I was wondering if anyone has made
> one of these and if so where did you get your parts?
Nothing in that little circuit is critical - the Radio Shack resistor
won't be 5k - the closest standard value will be 4.7k although this is
not critical - anything in the range of 1K-10K would be fine. Likewise,
no switch is really necessary since the plug itself will serve this
function. Any phototraansistor at all will do the job - if you end up
with a PNP transistor rather than the NPN BPW40 shown, simply reverse
the battery (or transistor) polarity. At a pinch, you could even file
the top off any TO-5 or TO-18 metal can transistor to expose the dice to
light, and ignore (or snip off) the base lead which will work fine too.
A dab of clear epoxy will keep the dirt out.
--
Richard Lindner [email protected] +61 (0)419 556 560
What a long, strange trip it's been
To: [email protected]>
From: Bob Shell [email protected]>
Date: Wed, 12 Dec 2001
Subject: Re: [camera-fix] Canon AE-1 shutter won't work at 1000?
> From: David Adams [email protected]>
> Date: Wed, 12 Dec 2001
> To: [email protected]
> Subject: Re: [camera-fix] Canon AE-1 shutter won't work at 1000?
>
> is 1/1000th of a second simply too fast for the eye to
> see?
>
Nope. It isn't really 1/1000 of a second on a focal plane shutter.
The fastest speed at which the shutter can move is the flash synch
speed, I think it's 1/60 second on the A series Canons. To get faster
equivalent speeds the shutter forms a slit, which gets narrower as
you set higher speeds, but the slit still takes 1/60 second to travel
across the film. This is a very often misunderstood aspect of
focal plane shutters.
Bob
To: [email protected]
From: "henrytaber" [email protected]>
Date: Sat, 29 Dec 2001
Subject: [camera-fix] Re: Getting Back to the Shutter Speed Tester - - - - - - - -
When I first started tinkering on old cameras I was fascinated with
homemade test equipment and built every piece I read about. The
soundcard shutter speed tester is one of the easiest...and best. But
I would advise you to make the "stereo" unit so you can check curtain
speeds too.
If you'd like to build some stuff you can check out my first few
projects on www.kyphoto.com/classics. Except for the Combination
tester (stereo tester)these are basically from Tomosy and internet
sources. Nothing too original or complicated.
In the test equipment pages there is lots of things to make. My
present homemade equipment is somewhat more sophisticated so I
haven't expanded the equipment pages any. Test equipment doesn't
seem to generate much interest. Those pages get relatively few hits
in comparison to the manual pages. Perhaps only a hundred or so hits
per month.
While on the subject... Anyone out there have a reasonably priced
(read dirt cheap and even broken) ZTS test unit to sell? Or any
other brand. I ain't picky.
Henry
From russian camera mailing list:
Date: Wed, 12 Dec 2001
From: "tigerarm2000" [email protected]
Subject: A simple way to test shutter speeds
Hello All,
After fixing a camera's shutter, I usually take off the lens and the
back and shoot the camera against a bright 21" TV screen at about 2
meters and use a good camera with accurate shutter speeds as
comparasin.when testing 1/1000 speed you can see a diagnal bright
band about 2mm wide running acorss the TV Screen,And with 1/500 speed
the width of the band doubles and so on until about 1/30" the TV
screen is totally bright.You can also tell if the exposure is even or
not. For an even exposure the width of the band should remain
unchanged.This is good only for focul plane shutters. I don't know
what is your way of testing shutter speeds? This message should have
been posted on the camera-fix forum but i post it here in case
someone may think useful.
Zhang
From russian camera mailing list:
Date: Tue, 08 Jan 2002
From: Javier Perez [email protected]
Subject: Re: Acceptable Shutter Speed Tolerance
The standard for all common horizontal FP cameras used to be 20%
But with some patience and a good shutter tester that measures
curtain travel time as well as overall speed you should be able to get
well within 10% on almost any well prepared camera.
Javier
[email protected] wrote:
>
> How accurate the mecjanical shutters should be? I mean, what
> tolerances are acceptable for, let's say, a Kiev-4, Contax, Leica,
> FED? Is it 1/2 stop? 50%? 25%? 1%?
> I've never seen any tolerances in any camera manual.
> Yuri
From russian camera mailing list:
Date: Tue, 08 Jan 2002
From: Bob Shell [email protected]
Subject: Re: Acceptable Shutter Speed Tolerance
[email protected] at [email protected] wrote:
> How accurate the mecjanical shutters should be? I mean, what tolerances are
> acceptable for, let's say, a Kiev-4, Contax, Leica, FED? Is it 1/2 stop? 50%?
> 25%? 1%?
> I've never seen any tolerances in any camera manual.
Factory repair manuals sometimes give tolerances.
More important if you can measure it is curtain travel time. Get that
right on for both curtains and the speeds usually fall into place.
Mechanical shutters can be set to very tight tolerances, as tight as you
want and are willing to pay the repair shop for, but they will drift out
faster than electronically timed ones.
More important than the speeds being right is knowing what they are. I
stick labels onto some of my cameras and mark the actual speeds on them.
Bob
From russian camera mailing list:
Date: Tue, 08 Jan 2002
From: Javier Perez [email protected]
Subject: Re: Acceptable Shutter Speed Tolerance
There used to be a company called cmr that sold
2 pocket testers, the delux model tested curtains.
But I haven't been able to find the company since
I saw their ad around 1985 for around $150, Worse case scenario,
It shouldn't be too hard to build a crude dual feature unit
using 3 prepackaged timer counters, a block with 2 sensors
and a simple gate gadget that starts and stops each one and resets the
counters.
I understand that the modern units use ccd sensors and provide
far more info such as curtain bounce and 1st and 2nd curtain speed
at several points down the plane including the edges where they are
prone to experience sudden decellerations if the brakes are bad.
They may even be able to provide a speed curve or fudged instantaneous
speed at any point (interpolated of course) But all I need is the speed
at the middle for now! Itwould be interesting to see how well linear
the old linear curtains really were or how how linearly accelerated
the accelerated ones were.
Bob Shell wrote:
>
> Javier Perez at [email protected] wrote:
>
> > My problem is that I've been trying for years
> > to get my hands on a cheaper tester with curtain speed but
> > nobody seems to make them. Any tester Without it is junk IMHO.
>
> I don't have one any more. I foolishly sold most of my test equipment
> when I shut down my repair shop. Needed the money at the time, but
> wish I hadn't. Mine was from a company in New Zealand, but I can't
> remember the name. Started with a Z or X. They were top dog in the
> late 70s when I bought it.
>
> No, I know of no inexpensive unit that can measure curtain travel
> time.
> If anyone comes across one, I'd like to know about it.
>
> Bob
From russian camera mailing list:
Date: Wed, 09 Jan 2002
From: Marco Pauck [email protected]
Subject: Re: Acceptable Shutter Speed Tolerance
....
Did you have a look at these schematics?
http://www.kyphoto.com/classics/testequipment.html
BTW, various aspects of shutter speed testing are discussed here:
http://medfmt.8k.com/mf/shutterspeed.html
I've already build a simple 'Use the soundcard Luke!' tester but
plan to build a better one. Any hints are welcome.
Marco
....
From russian camera mailing list:
Date: Tue, 08 Jan 2002
From: Javier Perez [email protected]
Subject: Re: Acceptable Shutter Speed Tolerance
The soundcard works ok but you'll need a front end
amp to get good sharp waves on the graph. otherwise
it saturates or something and you can't really tell when the thing
starts, which makes it impossible to get good readings on high speeds.
I was able to get something usable by masking off everything except for
a tiny slit in the diode. But it's still really clumsy.
With a stereocard it should be possible to
get the 3 readings using a properly made sensor block.
IE: two sensors to provide both c1 c2 and s
I've been thinking of building a dedicated GUI for it someday.
Javier
From russian camera mailing list:
Date: Wed, 9 Jan 2002
From: "Robert Chiasson" [email protected]
Subject: Re: Acceptable Shutter Speed Tolerance
Trivia first, that Australian company was "Zelox". They were out of
business by 1988, when I tried to buy their "Combi" tester.
Next, what do you call inexpensive? Last time I checked, a Kyoristu tester
was between $5,000 and $8,000, depending on features. For about (only)
$2,500 you could pick up a used Spectron CE240/CE360 Duplex sytem, without
light box (about $600 extra). Recently, there was a Honeywell CE240 with
sensors and CE241 light box for only $800 on eBay (I paid $200 for the
light box and a universal sensor). For a little over $4,100, there's the
ZTS Tester V-MC at Micro Tools (they may not stock it anymore, but you
could get from ZTS's Website). The Camline Model 22 shutter tester listed
for $885 in 1997. That's as cheap as you can go for a digital tester with
curtain speeds and 3 measuring points (that I know of, unless ZTS's
handheld meter does curtain speeds as well as shutter speeds, flash
exposure and normal exposures, for under $800). For about $250 including
shipping, you could buy a digital shutter tester from Micro Tools on-line
tonight and have it in your hands within a week.
It claims a 2 second to 1/4000 second range, but not curtain speeds.
I did have a schematic for a home-built single-channel
digital tester *with* curtain speeds, for under $200 with all new new
parts.
So, we want under a hundred bucks here? *Free* is what you really had in
mind???
You can use a TV to visually check curtain speeds for "correctness", this is
the cheap adaoptaion of the drum tester, which S.K. Grives exposes (the
Leica "Enigma Cipher Machine") on his Website. The problem would be to make
the drum from non-metal materials found at home or in a craft store and
still have it fireproof to the heat of the lamp - best idea I've had so far
is to just switch the lamp on while firing the shutter. Together with a
simple speed tester, you'll do just fine.
A cheap as possible simple shutter speed tester. Basically, you have 3
types - digital counter, analog capacitor charge meter, and visual. If you
have a digital frequency counter with a period function, all you need to add
is the photosensor switch. I recently bought a used one on eBay, we'll
have to see how that works out - I plan to use that under $2 Radio Shack IR
phototransistor the popular soundcard schematics call for. In the analog
department, Tomosy's circuit (except for the power supply) can be built for
about the same as one of those soundcard testers (~ $5), and I again bought
a VTVM off eBay to use as the meter and power supply. I chose a Heathkit
VTVM, because being a kit, they used standard components, had well labeled
circuit boards, have room for the camera tester extra parts, and since
VTVM's plug into the wall, there's a transformer (I hope) allready inside,
so I can get the 12volts the Tomosy circuit needs. I plan to run power to
the probe, which will have the phototransistor and capacitor circuit, and
just read the capacitor charge thru the VTVM input leads. As for visual, use
a cheap (eBay again) oscilloscope. I used a 5 kHtz triggered sweep scope
back in the late 70's for shutter testing, so a search should turn up a
suitable scope for under $25 (it's the shipping that will be expensive,
perhaps more than the scope). That's what I bought the Honeywell lamp box
and universal probe for. None of my eBay purchases have arrived yet
(including that Zenit-S from an certain list member in New York who sells
Russian cameras and has his own repairman), so I'll have to get back to you
when the results are in. There are photographic visual tests, but there're
not so cheap or convenient, so I'll skip them.
Shutter tolerences. The 1/2 stop tolerence is an accepted value, but
National Camera throws a twist at us by requiring that there be a 1 stop
variation *between* the speeds as well.
Happy adjusting.
------
Robert
from russian camera mailing list:
Date: Sun, 17 Feb 2002
From: "yupiter3" [email protected]
Subject: Re: Shutter adjustment ; Calumet Shutter tester
Here is the "Calumet Digital Shutter Tester" from Stephens link:
http://www.calumetphoto.com/images/products/AA8075.jpg
And description:
regards Philip
"Now, for a relatively small investment, you can monitor the
consistency of your camera or lens shutter. Features a six-digit LCD,
direct read-out with universal probe for focal plane and leaf
shutters. The LCD shows shutter times from as short as 1/100,000 sec.
to exposures up to 10 seconds and beyond without the nuisance of
calculating scales. A built-in voltage regulator offers constant
voltage over the entire life of the battery for consistent,
dependable readings. Requires one 9 volt battery (not included),
which provides up to 50 hours of use. Measures 2 1/2(w) x 4 7/10(h) x
1 3/5"(d).
Item No: AA8075 Qty Price(ea)
Regular Price 1 $89.99
From: Richard Fateman [email protected]
Newsgroups: rec.photo.equipment.35mm,rec.photo.equipment.medium-format
Subject: Re: Shutter Speed Tester
Date: Sun, 17 Feb 2002
There is a design here:
http://www.kyphoto.com/classics/shutterspeedtester.html
though actually I bought a used shutter speed
tester for $15 which is better than this, in that
it does not depend on the brightness of any light;
you shine any (sufficiently bright) light into the
lens, and hold the sensor at the film plane. The
capacitor is bleed off when the photo diode sees
any light, regardless of the amount of light.
There is a set of resistors to slow down the bleeding
proportional to the shutter speed setting.
(so you set "1/125" and get a fast/slow reading.
etc).
The tester I have was built by a company
Holdings of Blackburn
Mincing Lane/Darwen St.
Blackburn (England).
You might also note that the speed of the shutter
for a leaf shutter varies with the f-stop,
and depends upon the speed with which the blades
open and close. Thus at 1/500 of a second the
shutter may be FULLY open for only half that time.
If you build a digital readout, make sure you
understand what you are sensing, the maximum exposure
time or some integrated amount of light, or some
mixture.
also see
http://www.rit.edu/~andpph/text-shutter.html
Richard Fateman
Andy Tebben wrote:
> Is this what you are referring to?
>
> http://www.skgrimes.com/idcc/
From Russian Camera Mailing List:
Date: Thu, 7 Feb 2002
From: "Robert Chiasson" [email protected]
Subject: Re: Kyphoto "DIY" Shutter Meter
Comrades!
OK, progress: I increased the supply voltage to 15 volts, the 1" speed
needed a 12.8 kilo ohms series resistor (on the 100 k pot) to settle on the
1" shutter speed mark - 12 volts on the VTVM's 15 volt scale, same physical
position as 4 volts on the 5 volt scale initially used.
The closest standard value resistor I have is 12 kilo ohms, so I used it for
the 1" to 1/8" range, a 1.2 kilo ohm resistor for the 1/15" to 1/125" range,
and finally a 120 ohm resistor for the 1/250' to 1/2000' second range. These
resistors were all found in Radio Shack assortment #271-312A. The supply
voltage was reduced to 13.8 volts to "calibrate" the 1" speed. Things seem
sorta linear (most shutter speed indications "seem appropriate"), with the 2
faster speeds in each range being non-linear.
For a simple circuit, and not knowing the condition of the 'Cords's synch
contacts, I'm pleased with the results enough to proceed to wiring a
permanent version. Again, because it's a very crude design, I'm not going to
bother with trim resistors in the individual ranges, just an overall
"calibration" adjustment with the supply voltage. Well, maybe later, when I
can cross check with the 'scope and the digital counter. I think I'm closer
with this circuit that some of our favorite vendor's "shutter speeds seem
appropriate" claim.
For the greater glory of the Revolution,
------
Robert
----- Original Message -----
From: "Robert Chiasson" [email protected]
To: [email protected]
Sent: Wednesday, February 06, 2002
Subject: [russiancamera] Kyphoto "DIY" Shutter Meter
>
> I've breadboarded the circuit with 6 volt supply, a 20 kohm series resistor,
> and a Rolleicord substituted for the phototransistor, and a genuine VTVM
> (with tubes!).
>
> I got 4 volts at 1 second shutter speed, and about 2 to 2.5 at 1/5 second,
> using the 'Cord's synch contacts. IMHO, this validates the concept (and
> indicates that the 'Cord's shutter needs cleaning) and I will proceed to
> change to a 15 volt power supply and investigate what series resistors are
> required to provide 3 ranges: 1 to 1/8 second, 1/15 to 1/125 second, and
> 1/250 to 1/2000 second. Since the "Cord has the old series speeds of 1/5,
> 1/10 etc., those readings don't fit the linear scale I copied from the
> NatCam STAR tester. It seems that the 1/15 to 1/125 scale will need a series
> resitor of about 1.6 kohm, which is too small a value for the 100 kohm pot I
> was using.
From Russian Camera Mailing List:
Date: Tue, 05 Feb 2002
From: "ethnologist" [email protected]
Subject: Shutter accuracy competion
Dear All:
I read an earlier post on the $89.99 Calumet shutter tester
(calumetphoto.com) and decided I had to have one. It arrived today.
Then I thought it would be interesting to set up a Soviet vs.
Japanese shutter accuracy test using old cameras that I just happen
to have. All of these cameras are over 20 years old and have never
been professionally CLA'd to my knowledge. This "Shutter Superbowl"
would simply ask the question "Which of these old cameras are closest
to their marked speeds?"
The three cameras competing for the Soviets were a Zorki 4 (1958), a
Fed 5b (1980), and a Kiev 4AM (1981). On the Japanese side I had a
Beauty Super II (a little-known but great 1958 rangefinder with a
Copal SV leaf shutter), a Canon EF (ca. 1973 with a metal Copal
Square shutter), and a Canon AL-1 (ca. 1983 with an electronically-
controlled Canon cloth shutter).
I won't go into all of the testing details, but I followed the
detailed instructions sent with the Calument instrument. For me, a
given speed is "in spec." if it is within 20% of the marked speed, or
25% at the two highest speeds offered (1/250 and 1/500, or 1/500 and
1/1000).
Here is an overview of the results:
6. Beauty Super II. 0 of 10 speeds in spec. (0%) [1 sec. to
1/500]. On average each speed was 2.01 times slower than it should
have been, but the progression was very orderly. So I can easily
compensate by always setting one speed higher than that indicated by
the exposure meter.
5. Zorki 4. 5 of 10 speeds in spec. (50%) [1 sec. to 1/1000].
Average speed was 1.55 times slower than marked speed. "1/500" was
close to 1/250 and "1/1000" close to 1/500.
4. Kiev 4AM. 5 of 9 speeds in spec. (55.6%)[1/2 sec. to 1/1000].
The average speed was 1.21 times slower than the marked speed. As
usual "1/1000" and "1/500" were closer to the next lower speeds
3. Canon Al-1. 4 of 7 speeds in spec. (57.1%) [1/15 to 1/1000].
Average speed was 1.3 times slower than marked speed. "1/500" was
close to 1/250 and "1/1000" was 1/500.
2. Canon EF. 8 of 11 speeds in spec. (72.7%) [1 sec. to 1/1000].
The average speed was 1.26 times slower than the marked speed. This
was mostly due to the slowness of 1/500 and 1/1000, which were really
closer to 1/250 and 1/500 - a common result for many shutters.
1. Fed 5b. 7 of 9 speeds in spec. (77.8%) [1 sec. to 1/500].
Average speed was very accurate - 1.05 times faster than marked
speed! However this result is skewed by the result for the speed
marked "1/15" which was really 1/40 - totally unacceptable. If we
drop this one wacko speed from the calculation the average speed is
1.145 slower than the marked speed. This is still more accurate than
any of the other shutters in this test!
So my least loved camera - the ugly, clunky Fed 5b - won my little
competition. Obviously, this was not a professional evaluation under
laboratory conditions (and you will get different results if you try
something like this). But I'm impressed with the Calumet shutter
tester and had a lot of fun using it today. Also, I now know what my
speeds are and can compensate accordingly without having to pay a
technician for adjustments on all of these cameras.
Best wishes to all,
Bill Vickers
From Russian Camera Mailing List:
Date: Tue, 05 Feb 2002
From: "mlee777rf" [email protected]
Subject: Re: Shutter accuracy competion
Bill,
A quick comment about the 1/15 speed on your Fed 5b. The most likely
cause is the slow speed escarpment failing to engage at that
setting. It normally engages at speeds 1/15 and below. When you
fire the shutter, it probably sounds like 1/30 - "cherchop" insteed
of "cheeechop". I suggest you look up an older thred (2000+)...I
have it referenced at home, so will pass that info to you in a few
hours' time. You can adjust the clearance for this mechanism on the
camera.
I have the same problem with my 'new in the box' Zorki 4k. Rick
Oleson provides sketches on dismantling the Feds in this website at
http://rick_oleson.tripod.com I'm getting some help from him to
dismantle the advance lever on my 4k, which is the only item
preventing me from taking the top cover off. From there, adjustment
of the slow speed escarpment should be easy.
I'm still thinking about whether to get the $89 Calumet or the Micro
Tools device for $225. These devices are cheap compared to the
$2,500 and $4,000 devices from ZDT. Can the Calumet be used for
medium format cameras (6x4.5, 6x6 and 6x9), and how is it done
(different masks)?
Your results certainly suggest all ALL cameras regardless of vintage
or pedigree requires regular service. A Rolls Royce without regular
oil changes and adjustments will be out-lived by a well maintained
Plymouth Breeze. Russian cameras may have rougher finish and uglier
looks, but from a mechanical viewpoint are every bit
as "sophisticated"/complicated as today's highly prized Wetzlar
products.
The Fed's consistency suggests that it has been adjusted recently -
simple task if you have a meter since the adjustment screws are
accessible.
Mike
From Russian Camera Mailing List:
Date: Tue, 05 Feb 2002
From: "ethnologist" [email protected]
Subject: Re: Shutter accuracy competion
Dear Mike:
Many thanks for you very thoughtful response to my post. I'll think
about your advice concerning checking the escapement on the Fed 5b.
I have been doing some minor adjustments on my Russian cameras (light
seals, gluing trim, bending this or that, etc.), but so far I haven't
popped the lids on any of them. I have seen Oleson's disassembly
sketches and instructions on the web - I think they're great - much
better than going in "blind."
I think the Calumet tester can be used on medium format cameras - the
instructions show one mated to a Hasselblad. The main thing is to
get the "probe" at the film plane of the camera, and at the center of
the frame (the frame size doesn't matter). The tester doesn't look
like much (it's a plastic box with the metal "probe" at one end), but
it seems to work very well and costs much less than other
alternatives.
Best, Bill
...
From Russian Camera Mailing List:
Date: Tue, 05 Feb 2002
From: "mlee777rf" [email protected]
Subject: Re: Shutter accuracy competion
Bill,
May I suggest that you check out the following links on the use of
the Calument and its limitation at measuring higher speeds. This is
due to the probe measuring light at the centre of the lens, and not
taking the movement of the shutter curtain/blades into consideration
at those speeds.
http://medfmt.8k.com/mf/shutterspeed.html
http://hv.greenspun.com/bboard/q-and-a-fetch-msg.tcl?msg_id=002fyh
http://www.homestead.com/cameratester/
The 3rd link features the tester that Micro-tools sells for $225.
Its supposed to overcome the high speed "pessimistic" read-out
problem.
Hope its useful.
Mike
From Panoramic Mailing List:
Date: Wed, 06 Mar 2002
From: ADavidhazy [email protected]
Subject: Re: Monopods/Shutter speed tester
> 2. I remember seeing an article on how to check shutter speeds by using a
> phonograph. Does anyone know how that is done? I have an old Thornton
> Pickard roller blind shutter I want to use.
check this out: http://www.rit.edu/~andpph/text-shutter.html
regards,
Andy
shutterspeed.html
from camera fix mailing list:
Date: Fri, 08 Mar 2002
From: "stuey63au" madfamily at bigpond.com
Subject: Re: Monopods/Shutter speed tester
Hi all,
Don't know if you're interested, nor if the product is any good, but
this electronics magazine has an apparently easy to make shutter
tester in it. The mag is out of print (July 2000) but they send
copies of articles.
http://www.epemag.wimborne.co.uk/0700.htm
Mark
...
From Camera Maker's Mailing List:
From: "ZoneV" [email protected]
Subject: Re: [Cameramakers] Monopods/Shutter speed tester
Date: Fri, 8 Mar 2002
Hello,
probably the following method is good for you, Mr. Grimes write, it works
only with times shorter tahn 1/60 second.
http://www.skgrimes.com/idcc/index.htm
S.K.Grimes Leicalike Shutter Speed tester.
Markus
From Camera fix mailing list:
Date: Fri, 08 Mar 2002
From: "stuey63au" madfamily at bigpond.com
Subject: Re: Monopods/Shutter speed tester
Hi all,
Don't know if you're interested, nor if the product is any good, but
this electronics magazine has an apparently easy to make shutter
tester in it. The mag is out of print (July 2000) but they send
copies of articles.
http://www.epemag.wimborne.co.uk/0700.htm
Mark
From Camera fix mailing list:
Date: Fri, 8 Mar 2002
From: "Robert Chiasson" [email protected]
Subject: Re: Re: Monopods/Shutter speed tester
For the "Haynes Shutter Checker", the range was 1/2" and 1/500". This device
was produced before 1965 (source - "The Amateur Photographers Handbook", by
Aaron Sussman, 7th edition 1965).
I don't have access to my National Camera lesson that details this procedure
(using a 1/2 degree protractor). At the high speeds comparative eyeballing
was used a lot. In the days this test was used, shutters rarely got above
1/300". For the high speeds, the recommended technique was "count the lines
in the pic of the TV" - 525 lines @30 interlaced scans a second (whatever).
Real keeners used an oscilloscope. And a privileged few (factory trained in
Europe) used a drum tester.
------
Robert
From Camera fix mailing list:
Date: Fri, 8 Mar 2002
From: "Robert Chiasson" [email protected]
Subject: Re: Re: Monopods/Shutter speed tester
...
> While we are on the subject of speed testers. Has anyone tried the
program (for old commadore) that Tomosy included in book 1 ? I am just
curious to find out if it works. or any other comment. My homebuilt tester
starts to get eratic at 1/250 so I get the slow speeds close and the higher
speeds are uneducated guesswork. I suspect that my old RS Coco could be
easily substituted for the Commadore. At the moment it's taking up space in
the attic. Who would throw away a perfectly good 135k computer :-)
> Everett
I've never tried it, but realize that the C64 has a digital joystick, while
the Co-Co has an analogue joystick. You would have to build an A/D
interface?
National Camera taught us to get 1/15" as perfect (modern Synchro-Compur) as
possible, check the pallet engagement at 1", then the rest would be where
the design of the shutter and the mainspring's health put them. Maizenberg
says to get 1/10" (old Compur copy) as close as possible, then good design
is supposed to take care of the rest. All this assumes *you* have skillfully
cleaned and lubed the shutter to perfection (and installed new springs).
The standard home shop electronic tester was the SynchroTester, with a high
volume shop using the Motion Analyzer (an oscilloscope based instrument).
------
Robert
From Camera Fix Mailing List:
Date: Fri, 8 Mar 2002
From: [email protected]
Subject: Re: Re: Monopods/Shutter speed tester
[email protected] writes:
> Does
> the 555 timer circuit used as frequency source hold it's value? Does it need
> to be tuned at regular intervals?
I look at it once in a while on a digital freq.counter. It holds very,very
well if you use a high quality capacitor.
Of course, you could always use a more sophisticated xtal controlled osc.,
but I never found a need for that degree of accuracy.
The ckt. is just a counter with a 3-digit display. A constant light source is
used in front of the lens, with the darlington photo transistor at the film
plane. When the shutter opens, the thing starts to count. When the shutter
closes, it stops. It interval is displayed on the 3-digit readout in 3
decades: 100Hz,1kHz,10khz.
Roland F. Harriston
From Camera Fix Mailing List:
Date: Sat, 9 Mar 2002
From: "Robert Chiasson" [email protected]
Subject: Re: Re: Monopods/Shutter speed tester
Hmm, LED's are an interesting concept. For shutter timing, should be
possible, but not for exposure testing. I did buy one of those Radio Scrap
matched IR emitter and detect or pairs for experimentation - there's a
factory technique of setting up a counter to calibrate leaf shutters I want
to play with - later (w-a-y later, right now).
I have plans for a lamp box covering the range desired, but first comes the
shutter "tester" (not merely an "indicator", that circuit is available
everywhere for the last 30 years).
Think DC power supply for an automotive bulb (or low voltage halogen bulb),
using mechanical light reduction (Waterhorse stops) in a cylinder
surrounding the bulb.
------
Robert
From Camera Fix Mailing List:
Date: Sat, 9 Mar 2002
From: Mark Overton [email protected]
Subject: Re: Question about testing shutter speeds
Kenith Ryan wrote:
> I have been following the recent thread on shutter testers with interest
> and now have a question. What aperture should I use for testing leaf
> shutters? I have been using the maximum aperture thinking that more light
> would give a better reading, but now I am not sure.
The maximum effective speed occurs when the lens is wide open, and I think
this is the speed engraved on the shutter's speed-ring. However, when
shooting, you want to know the effective speed you're getting at whatever
f-stop you're using. So I suggest checking it at your common f-stops
and factor-in those speeds when you run film through it.
Note that f-stop has a substantial effect on effective speed only at the
highest couple of speeds.
Also, the fastest speed engraved on most leaf shutters is 1/500, which
seems to be a joke: 1/500 is usually 1/3 to 1/2 stop slow, even when
the remaining speeds are reasonably accurate.
Mark Overton
From camera fix mailing list:
Date: Thu, 7 Mar 2002
From: Mark Overton [email protected]
Subject: Re: Monopods/Shutter speed tester
Tim wrote:
> I am in the process of making a very accurate shutter
> speed tester.
>
> It uses low cost process control electronics and may
> be 0.1% accurate or better.
>
> Is that of interest?
You first might want to consider buying Tomosy's shutterspeed tester
that he has put into production. The link is:
http://camlogix.com
This device is smart enough to tell you the effective time the shutter
is open, instead of the less useful (but easier to measure) total time.
I own one, and am completely satisfied with it.
Tomosy appears to rely heavily on analog electronics internally,
although the readout is digital. As a result, his tester is not able
to display speed+error (or even speed); it only displays time.
For example, I'd like to see "250 - 12%" on the display, meaning the
shutter fired at 12% slower than 1/250, but Tomosy's will display
"4.5" instead (this is the shutter-open time in milliseconds). It has
a table of time-speed numbers on the front, so I can quickly see that
1/250 should take 4 msec, so I know that 4.5 msec is a bit slow, but
having the speed on display directly would be more convenient. Hey,
I'll even settle for a display of "222" meaning it fired at 1/222,
and it'll be obvious that my shutter is a bit slow.
Mark Overton
From camera fix mailing list:
Date: Thu, 7 Mar 2002
From: Mark Overton [email protected]
Subject: Re: Re: Monopods/Shutter speed tester
For leaf shutters, it helps if the tester can tell if the blades are
partly open, and compensate for the opening and closing times. This
will allow you to compute effective time instead of simply the total time.
If you measure total time, your times will be too long for both leaf
shutters and focal plane shutters at the highest speeds.
Tomosy's tester does this. It uses an external light source (a soft
light bulb in front of the camera), and you calibrate the tester with
the shutter open, so the tester knows how bright full-open is. Then
it can interpolate the opening and closing times.
Mark Overton
From camera fix mailing list:
Date: Thu, 7 Mar 2002
From: "Robert Chiasson" [email protected]
Subject: Re: Re: Monopods/Shutter speed tester
Adding a bias circuit to a digital design is a snap. I've never seen one in
an analogue tester, but I will have to try and design one (I know the
theory, making a reliable and cheap circuit from locally available parts is
the catch).
Without the bias circuit, the calibration is a bit more involved. With a
leaf shutter, the procedure is to decide what f-stop you want to test at,
then set the counter to trigger at 1 stop down. Now the tester is
compensated for the open and closing times at the higher f-stop. National
Camera recommended testing at f5.6, as did most other manufactureres. When
the digital counters first came out, testing at f8 was common (older, slower
lenses in those days, and bigger negatives).
------
Robert
...
From camera fix mailing list:
Date: Thu, 7 Mar 2002
From: Mark Overton [email protected]
Subject: Re: Re: Monopods/Shutter speed tester
Robert,
You've got a fun project going there. Make me drool, why don't you. :-)
> Adding a bias circuit to a digital design is a snap. I've never seen one in
> an analogue tester, but I will have to try and design one (I know the
> theory, making a reliable and cheap circuit from locally available parts is
> the catch).
Yes, the Tomosy tester is setting a bias. In fact, the calibration knob
is labeled BIAS. You open the shutter, and turn the Cal knob until the
indicator LED lights. That establishes what full intensity is, and his
tester triggers at half that intensity.
He uses just one sensor, which has an opening of just a couple mm.
This is mounted on a block which fits on the film-rails.
To measure speed-variation across the focal plane, you take two measurements,
one at each end. Cameras from the 60's and older often have large variation.
Instead of using pulses, why don't you use a constant light source in front
of the camera (such as a tungsten bulb), and feed the output of the
phototransistor (or whatever the sensor is) into an A-to-D? Then the Pic
could see the rise and fall as the edges of the curtains pass by, or the
opening and closing of a leaf-shutter's blades. You could sample the A2D
as fast as the Pic can go to get good accuracy. If you had a good LCD
on the tester, you could even display the waveform.
Mark
From camera fix mailing list:
Date: Fri, 08 Mar 2002
From: "timowlett" [email protected]
Subject: Re: Monopods/Shutter speed tester
How did this work in practice ? What shutter speeds could you test,
and at what speed setting on the turntable ?
Looking at the calculations ( included below ), it appears that this
technique would not allow you to time your shutter for the faster
speeds without the use of a macro lens and expert timing.
As this techinique is obviously used, does this imply that the faster
shutter speeds do not need to be checked - that they are explicitly
linked to the slower speeds (which you can check) ?
Here are my calcs :-
Assuming a turntable at 45 RPM, and a 30cm (Yes, I'm a metric boy) LP.
45 x 360
-------- = 210 deg of rotation per second.
60
Measuring a shutter speed of 1/1000 of a second.
Degrees travelled by the record during that time
= 210 x (1/1000) = 0.21
Circumference of a circle = 2 x PI x radius
=> Length of Arc travelled by white spot
= 2 x PI x 15 x ( 0.21 / 360 )
= 0.055 cm (2 sig figs).
Is it possible to measure 0.5mm accurately on a photograph of a
record without (as I mentioned) using a macro lens ?
Tim.
--- In camera-fix@y..., "Robert Chiasson" rchiasson@s... wrote:
> Just photograph a 1/8" white mark rotating on the turntable, then measure
> the arc with a protractor. Do the math and find out what part of a second
> the photograph shows the shutter was open.
>
> In the old days you could buy a cardboard disk "shutter speed tester" that
> had the white mark and also instructions printed on it.
>
> ------
> Robert
From: "Bob Fowler" [email protected]
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Shutter Speed Tester? (Where to buy? Or how to do?)
Date: Thu, 21 Mar 2002
FWIW - I have the DCA-1 shutter tester that was part of the now defunct
National Camera camera repair course. I don't know if they are still
available (National Camera went belly up over 10 years ago). It came in kit
form, but the probe (the hard part) was pre-assembled. The unit measures
shutter speeds for leaf and focal plane shutters as well as curtain travel
time for focal plane shutters. Mine has been an important part of my studio
for about 12 years now. I check all of my camera shutters every couple
months "just in case."
I don't have any experience with the Calumet tester, but from what I've
heard, it's a good unit to have around.
ZTS Inc. makes a full line of testers, but they are a lot more expensive.
You can see them at their products page found at http://www.ztsinc.com/ .
If you're handy with a soldering iron, check out Henry Tabors web page at:
http://www.kyphoto.com/classics/testequipment.html He has plans on line to
build all sorts of simple test equipment.
This page: http://www.geocities.com/Yosemite/2131/shspeed.html has
information (in German and English) for making a sound card based tester.
The sci.electronics.repair FAQ located at:
http://www.repairfaq.org/REPAIR/F_audiofaq.html has some other general info
that may be of help (especially chapter 9).
http://groups.yahoo.com/group/camera-fix/links is an excellent source for
links for various repair related web sites.
And for the cheapest of all methods, try
http://home.worldonline.dk/~lhaven/Shuttertest.html
Hope this helps.
--
Bob Fowler
[email protected]
From camera fix mailing list:
Date: Wed, 27 Mar 2002
From: Tim Moore [email protected]
Subject: Re: Testing Shutter Speeds - Tim's Way
The current state is:- The pulse generator's complete
(software & hardware) the IR source has been taken to
500 k pluses per second (more than enough).
The sensor matches the generator.
The counter software works but needs refining.
The LCD software works but needs significant work for
user friendly display. (hey! who wants to convert hex
to fractions of a second! hehehe...) . (not
difficult, the tricky bit is complete)
So all progresses well.
Having fun here!
Tim
PS For those who have not followed this and earlier
threads, a small (cheap) PIC processor generates a
series of very fast pulses and then detects a count
and processes that info into a shutter speed.
For acceleration of the opening shutter (ditto for
closing shutter) and loads of other details, multiple
IR sources and sensors should do the trick. (In the
fullness of time)
From camera fix mailing list:
Date: Fri, 29 Mar 2002
From: Mark Overton [email protected]
Subject: Re: Best shutter testers?
I own the Camlogix, and have heard about the Calumet.
The Camlogix has additional circuitry in it to give you *effective*
shutter speed for both leaf and focal plane shutters. I've heard that
the Calumet does not do this.
Mark Overton
-----
> What do you recommend for shutter testers?
From camera fix mailing list:
Date: Fri, 29 Mar 2002
From: "Bryant Wetzel" [email protected]
Subject: Re: Timing Leica/Russian shutters at highest speeds
Mark,
Well, those darn Russians did copy the Leica design pretty good. Put the
camera on B. You need to set the first curtain to 17ms from start to finish.
Then set the closing curtain to 17ms. ( gasp ). That is pretty tough to read
on a shutter tester with only one sensor.
The book says to set the first curtain and then wind the second curtain
up by a set amount of turns. Then you are supposed to set the speeds. It
seems a lot more finicky when I do it that way.
Then go by and set the top speeds starting at 1/1000, the bottom speeds
starting at 1/30, and finally set the 60th. Then go back and check them all
again. ( you will have to make adjustments ). The above is how I do it, you
may want to do it otherwise and of course, your mileage may vary. The slit
width should remain fairly constant across the board. You also want to check
the channel the shutter runs in for damage and be sure that you have lubed
all four spots on the single/split roller side of the shutter.
In general, if the camera was set up properly to begin with, and has not
been "adjusted", you can set the travel times and the speeds will fall in
line.
A properly set Leica will seem to have a 'lazy' first curtain. That is
one of the reasons they are so quiet. It is also the reason that one needs
to know the opening times for each curtain, closing times for each curtain,
slit width, and total curtain travel times when setting a shutter properly.
And, Yes, it is possible to properly time a Russian shutter of Leica design.
Bryant
...
from camera fix mailing list:
Date: Fri, 22 Mar 2002
From: "rick_oleson" [email protected]
Subject: Shutter Speed Testing (was: Re: Asahi SP1000 problems (shutter, meter)
Another variation on this theme, i don't know if it's been discussed
recently (i'm not real good about keeping up with the discussions) is
to look through the shutter at a blank computer monitor (a blank word-
processing document is great) as you fire it (with the shutter
curtains traveling horizontally). Like the electronic-flash test,
this works only at the higher speeds, best at about 1/250 and up, but
it gives you a very good impression of the shutter's uniformity or
fade behavior. You will see a dark screen with a diagonal white band
across it; the width of the band is proportional to the shutter time
(and the same as the width of the illuminated slit for the same speed
in the flash test), and it should be uniform for the length of the
band. If the band tapers from one end to the other, the shutter is
fading... this is easy to detect with this test even if the shutter
does not completely cap during travel.
You can even quantify the results if you have time: just load the
camera, put the lens back on and photograph the screen several times
at each speed - then the width of the bands and the amount of taper
can be measured on the negatives or prints. i use a digital tester
for basic speeds, but still use the monitor to test for fade at the
top speed or two.
rick :)=
Date: Mon, 30 Dec 2002
To: Russiancamera-user [email protected]
From: Paul Shinkawa [email protected]
Subject: [Russiancamera] Re: Sutter speed measurement
There is a tester which can acquire data to be analyzed using Cool-edit. the
URL is here:
http://www.geocities.com/Yosemite/2131/shspeed.html
There are also some other testers documented at these web sites. I have
acquired the the Radio Shack parts to build the kyphoto-LED version, but
haven't had the time to assemble it yet.
http://www.kyphoto.com/classics/shutterspeedtester.html
http://www.skgrimes.com/idcc/
-Paul
From camera fix mailing list:
Date: Sat, 14 Dec 2002 08:42:47 -0800
From: Gene Poon
Subject: Re: Re: "Capping" and Focal Plane Shutter Tester
[email protected] wrote:
> I need some help/advice:
>
> I'm working on a Mamiya 1000 TL SLR that exhibits "capping" and I would like
> to correct the problem. The shutter operates real nice and the curtains are
> in excellent conditon, but photos are black on one side of the frame. I
> believe this evidences "capping".
>
> The only shutter test instrument I have is just a simple device with a
> phototransistor and counter circcuit to measure how long a leaf shutter is
> open. I think I need more than this to do a focal plane shutter job.
>
> I have identified the two rachet wheels for adjusting the shutter curtain
> tension located on the bottom of the chassis, but I need to know how to set
> them up and I need a simple (but effective) tool/instrument for
> setting/checking speeds.
>
> Is there an instrument that I can make from easily obtainable electronic
> components?
>
> Any advice will be most appreciated.
First, verify capping by taking off the lens, opening the back, and
watching through the focal plane to a steady light source (daylight,
incandescent light bulb) as you fire off the shutter at various speeds.
This should give you a guide as to what you are doing as you adjust
the curtain travel.
To see the actual slit width: you are sitting in front of one piece of
easily obtainable electronic component.
A rough check...by no means accurate, but enough to give you an idea
that what you are doing is working...is to take off the lens, open the
back, hold up the camera to your computer monitor (I do this on a CRT
monitor, don't know about flat-screens because I don't have one), and
release the shutter a few times at 1/1000 or 1/500. Over several
different releases you should be able to see the slit width at different
points in its travel, since the screen flickers at a far lower duration
than your shutter speed. It should NOT be exactly equal from one side
to the other because the curtains should be moving faster at the end of
travel than at the beginning, due to their acceleration.
You MIGHT then be able to use your existing leaf shutter tester and a
mask (to limit its field of view) to compare shutter opening duration at
one end of the focal plane vs. the other. This won't allow measurement
of the actual curtain travel time, though. On Pentaxes which are
susceptible to capping, I begin by adjusting only the opening curtain
faster, since that one is more prone to slowing down. I would not know
which adjusting point handles which curtain on your Mamiya, though. And
it may turn out that the 20-plus year old shutter needs a CLA anyway,
which will require more disassembly.
-Gene Poon
From camera fix mailing list:
Date: Sun, 15 Dec 2002
From: "Mark Stuart madfamily at bigpond.com
Subject: Re: "Capping" and Focal Plane Shutter Tester
Roland, this link may (or may not) be of use. I haven't tried it.
http://www.kyphoto.com/classics/combinationtester.html
Mark
From camera fix mailing list:
Date: Sun, 15 Dec 2002
From: "Rick Oleson [email protected]
Subject: Re: "Capping" and Focal Plane Shutter Tester
I use the "CRT" method to detect capping too, and use a digital
tester to find the actual speed accurately.
actually, on the CRT, the white stripe SHOULD be exactly constant in
width. the acceleration of the curtains causes the line to be
slightly curved rather than straight, but the width is a function of
the time of exposure and it should stay constant if the shutter's
running true.
this is a very fast, easy and effective method, as well as being free.
rick :)=
From camera fix mailing list:
Date: Sun, 15 Dec 2002
From: "JMS" [email protected]
Subject: Re: Re: "Capping" and Focal Plane Shutter Tester
This method will not work on a LCD screen as they do not "scan" to display
as a CRT does. This is one reason that they are easier on the eyes, no strobing
or flickering.
Take Care and God Bless,
John
[email protected]
From camera fix mailing list:
Date: Tue, 18 Feb 2003
From: "Robert Chiasson" [email protected]
Subject: Re: quickie shutter check
Rick,
I've already downloaded it, thanks.
Folks should also check out Steve Grimes drum tester page for tips on
reading the trace:
http://www.skgrimes.com/idcc/index.htm
In other news - that "bring infinity indoors" - if I wanted to check focus
at 10 feet insted of infinity, do I set the known good lens to 10', and the
turn the test camera lens until it's sharp, and then relocate it's focus
scale to read 10'??? (I have a 21mm that needs adjusting)
------
Robert
----- Original Message -----
From:
To:
Sent: Tuesday, February 18, 2003
Subject: [camera-fix] quickie shutter check
> i don't know if anybody's interested, but i posted a page on using
> your computer monitor as a shutter tester on my website. it's at:
>
> http://members.tripod.com/rick_oleson/index-135.html
> rick :)=
From camera fix mailing list:
Date: Wed, 19 Feb 2003
From: "Rick Oleson [email protected]
Subject: Re: quickie shutter check
If you just want the lens to match its rangefinder or groundglass,
it's pretty easy: just focus at the desired distance and check the
viewfinder against a groundglass in the film plane. To check against
a "known good lens", though, you are (i guess) checking the accuracy
of the distance marking engraving on the lens barrel of both lenses.
This also brings in the question of whether it's 10 feet to the film
plane, or 10 feet to the lens. the film plane is generally the
standard reference... but not all cameras have the film plane marked
on the outside for convenient measurement; and if the lenses are from
different makers, they may not have used the same reference for
measurement. depends on how critical the focus is, too... on a
100/2.0, a couple of inches at 10 feet can make a difference...
rick :)=
From camera fix mailing list:
Date: Wed, 19 Feb 2003
From: "Rick Oleson [email protected]
Subject: Re: quickie shutter check
i've seen that link before. the effect of the drum tester is
identical to the TV screen, both are scanning a horizontal ine
rapidly down the screen. it would be possible on either, i suppose,
to mark the "correct" angle for normal curtain velocity on any given
camera. it's a pretty handy tool in either form, and you can read
speeds with surprising accuracy once you get used to it.
rick :)=
From camera fix mailing list:
Date: Wed, 19 Feb 2003
From: "Rick Oleson [email protected]
Subject: Re: quickie shutter check
Yes - at 1/60 second the entire screen has been scanned. i think it
actually scans every other line and fills the entire screen in 2
interlaced scans in 1/30 second, but once the first 1/60 second pass
is done it becomes pretty hard to distinguish between the dimmer and
brighter zones. (as a bit of trivia, ricoh's XR-P model had a
special "TV" shutter speed which was a very precisely adjusted 1/30
second set to exactly match the raster rate of a tv screen to give
images with no funny bright stripes in them)
rick :)=
From camera fix mailing list:
Date: Wed, 18 Jun 2003
From: "rbraun_04062" [email protected]
Subject: Re: shutter speed test
Shall one assume that if a camera is firing correctly on 1/1000, 1/500, 1/250 then it fires correctly at slower speed?
Rb
--- In [email protected], Gene Poon sheehans@a... wrote:
> rbraun_04062 wrote:
> >
> > Sems like a happy bunch here. I'm still chuckling about the beer test.
> >
> > Perhaps you'll chuckle about the next question.
> > How do you test the shutter firing at correct speeds? Someone told me that a $4000 is needed. I'm thinking that a group that can come up with a beer test has figured out how to do it cheaper.
> >
> > One idea is to have some moving object capable at moving at precise and adjustable speeds (like a Lionel train or something and determine proper speeds with a camera you trust to be accurate. If you arrive at sharp pictures within these speeds then you might have a reasonable results.
> >
> > ... Or is there a better way?...
> >
>
> A phonograph turntable works.
>
> Put a record on it, with a piece of narrow white tape from the center
> (centre, outside the USA) to the edge of the black record. Put it on
> the platter, and turn the unit on so the record spins. Take a photo of
> the spinning record. Figure out how long it takes for the white tape to
> rotate the amount that you see on the photo, based on the rotational
> speed (33 1/3 rpm, 45.00 rpm, 78.26 rpm are the standard speeds).
>
> Most turntables are calibrated closer than we even DREAM our cameras
> could be; within +/- 2% on most good-quality consumer turntables, and
> within +/- 0.3% on NAB-standard professional models. That, of course,
> was before you put your turntable on the shelf when you switched over to
> CDs, years ago. Maybe now it won't even run...
>
> Gene "I Still Listen To Vinyl" Poon
From camera fix mailing list:
Date: Tue, 17 Jun 2003
From: "keith" [email protected]
Subject: RE: shutter speed test
Why are we concerned with 3% tolerances in shutter speed when the successive
shutter speeds available on our cameras differ by 100% and the f stops
differ by 60% to 70%? The shutter speed tolerance becomes more meaningless
when we see how forgiving film processing is.
Some time ago someone ran this shutter speed test on one of these groups
using a tv set. All bets are off if you have HDTV.
http://members.tripod.com/rick_oleson/index-135.html
Date: Sun, 3 Aug 2003
From: Matt Denton [email protected]
Subject: [Russiancamera] TV Shutter Speeds (was 'Zorki 4K Body, Case for Sale $15.00')
To: Russian Camera Users [email protected]
Rick Oleson has a great little page devoted to the TV technique:
http://members.tripod.com/rick_oleson/index-135.html
Sound just means it 'sounds right' compared to a camera that has
correct speeds, or that each speed sounds like it's about twice the
previous speed.
>Can anyone point me to the sound and TV test techniques?
>
>Thanks in advance!
From camera fix mailing list:
Date: Tue, 16 Sep 2003
From: "ned99992001" [email protected]
Subject: Re: Shutter Tester!
--- In [email protected], "Vincent" jonyquik@n... wrote:
> Check out this ebay offering.
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2951223828&category=30038&rd=1
Any one bidding on this might want to contact CRIS to make sure the
tester is still supported by Kyoritsu. I picked up a EF5000 a few
years ago at an auction for $125.00, it was a year old and sold new
for $8,000 plus. The medium format sensor I picked up last year was
$1900.00 new. The EF-511NK2 might go fairly cheap, go for it Gene :)
Mike
From camera fix mailing list:
Date: Tue, 18 Nov 2003
From: Mike Willegal [email protected]
Subject: Re: Shutter Tester Software
For those that are interested, I posted the Mac OS X sound card shutter
tester software on my website. It is free to download and try. Let
me know about any successes or failures you have (I expect more
failures than successes). Don't expect me to provide any fixes. I'd
rather spend my time looking into a USB based shutter tester design.
Regards,
Mike Willegal
www.willegal.net
From camera fix mailing list:
Date: Sun, 16 Nov 2003
From: Manfred Mornhinweg [email protected]
Subject: Re: shutter tester
Hi Mike, and all!
> I'm toying with the idea of building a USB based shutter
> tester that I can make more accurate and use across a variety of
> platforms.
I'm also toying with a similar idea. What I have in mind is a small PIC
microprocessor, interfaced to two photodiodes, and to a serial port. The two
sensors would be located in opposed corners of the picture field, mounted on a
small 35mm wide metal plate that can easily be put against the film rails of
the camera. The camera would be held against a light source and the shutter
triggered. The firmware would wait for the first sensor to receive an increase
of light, then start counting time, in parallel, until the second sensor
starts getting light, until the first stops getting it, and until the second
one stops. Then it would send the results out through the serial port:
Exposure time at opening side, exposure time at closing side, average exposure
time, first curtain travel time, second curtain travel time.
Any computer or portable terminal could be used as display. The entire thing
would cost barely 10 dollars in parts. It could even be powered from the
serial port. As an alternative, the tester could be fitted with its own
display and power source, becoming independent of a computer, but that would
drive up the cost to about 40 dollars.
I already got the PIC for this project. Now I need the time to develop it!
> I spend far too much time reading email like this instead of
> working on my little projects. :-)
Same for me! :-(
We should declare an e-mail-less week every month, so we all can get some
useful work done!
Cheers,
Manfred.
Visit my hobby website!
http://www.qsl.net/xq2fod
From camera fix mailing list:
Date: Sun, 04 Jan 2004
From: Abdon Gonzalez [email protected]
Subject: Re: shutter speed tester experiences
Lets see.
The real world speeds are:
1/30 .03125
1/60 .01563
1/125 .00781
1/250 .00391
1/500 .00195
1/1000 .00098
The distances from one stop to the next are:
1/30 to 1/60 .01562
1/60 to 1/125 .00782
1/125 to 1/250 .00390
1/250 to 1/500 .00196
1/500 to 1/1000 .00097
Regardless of latency, you would expect to see the distances from one
stop to the next fairly accurate.
Now, I am not familiar with the idiosyncrasies of the Leica III (yet),
nor your tester, but it seems that the 1/30-sec is way too slow. If your
speeds are all nice and constant, it looks like all of them might be a
bit slow. I would raise both curtain tensions a tad (while keeping an
eye for capping, flash sync, and start/end travel) to shorten all times
at once. The good news is that your spread looks good. Do the TV test,
that doesn't lie and will give you a better idea of how accurate your
top speeds are.
By the way, I have a Nicca on my to-do list. I might tap you for some
advice latter on :)
- Abdon
...
From camera fix mailing list:
Date: Sun, 04 Jan 2004
From: Gene Poon [email protected]
Subject: Re: shutter speed tester experiences
Vick Ko wrote:
> Abdon, Happy New Year.
>
> Can you briefly describe the "TV test" ? I've read it somewhere before.
It's on Rick Oleson's site (which has a lot of other good stuff, too).
Note that it is only works from 1/60 up because it is based on the scan
of a television, or...what I like even better...your computer monitor.
I open Wordpad and maximize it to get a full white screen.
"You already own a good shutter tester! Here's how to use it" is at:
http://rick_oleson.tripod.com/index-135.html
The index page to all his camera repair stuff is:
http://rick_oleson.tripod.com/index-27.html
Don't blame me if you spend a couple of hours looking over all his pages.
-GP
From: Denis Pleic [[email protected]]
Sent: Thu 1/22/2004
To: Monaghan, Robert
Subject: Possible link for your Medium Format site
Hi Robert,
I'd like to propose another link for your Medium Format mega site.
I've done a few Web pages dealing with my DIY projects, which were
mostly inspired by the articles from your site.
I've got three pages, dealing with:
1) Using Palm Pilot in the darkroom to drive the enlarger, in
conjunction with freeware program "Foto Timer", resulting in
"computerized" exposure control of prints;
2) Lens hacks for 2x3 Speed Graphic: adapting a Rolleiflex Xenotar
80/2.8 and another barrel "long focus" lens for the Speed Graphic;
3) DIY shuter speed tester - done from the scheme mentioned on your
pages.
All pages are illustrated, and the "Speed Graphic Lens Hacks" also
has sample photos taken with those "hacked" lens.
Finally, the link is:
http://open.hr/~dpleic/photo/photo.html
Regards,
Denis Pleic
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