Photo courtesy of Chuck Rubin [email protected]

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medium format camera pages site. There is also an excellent Rollei Mailing List which has a lot of postings on Rollei TLRs (and SLRs!).

[Ed. note: thanks to Todd for sharing these historical notes!...]
From Rollei Mailing List:
Date: Tue, 24 Oct 2000
From: todd [email protected]
Subject: Re: [Rollei] Rolleiflex 3.5f newbie question

The alleged conversation regarding the early 3.5 Fs took place between Marc and myself over a year ago. It was pointed out that the 1st series of 3.5 F (2,200,000-2,219,999) had, in fact, a modified EVS lock under the f-stop wheel.

To effect this shutter in 1958, Compur developed a third ring between the upper shutter speed ring and the lower aperture ring. The effect of this was if the shutter speed ring was turned towards slower speeds and the aperture ring towards smaller apertures, the EV setting would be retained. Any separate movement of either the shutter ring or the aperture ring would cause the meter needle to deflect through a complex linkage.

Due to the enlargement of the shutter (the gears ran on the outside of the shutter proper) the taking/viewing lens distance was increased to 45 mm from 42 mm as in the 2.8 models. Since nobody at Rollei had been able to gather experience with the mechanical coupling of shutter and meter follow pointer, the EV coupling of the previous models was essentially retained in the coupled meter of the first model of the 3.5 F. However, after 20,000 cameras, the EV part of the meter coupling system had to be abandoned as seemed to make the shutter and aperture wheels rather stiff to operate.

The second version of the 3.5 F (2,230,000-2,241,500) was developed which again had the same shutter, but no EV control. Still a certain stiffness was found in the wheels, due to the additional gear transmissions and the large friction diameter of the three rings at the shutter proper. After 11,500 cameras, this version was abandoned.

With high demand for a 2.8 F version with coupled meter, the Rollei engineers were spurred to find a solution for the 3.5 F that they could apply to the 2.8 F. The Rollei engineers developed a small bevel gear differential which reduced the high torque of of the control dials of the previous models and was a solution they could apply to the 2.8 F. It also rid the shutter of the planetary gears that caused such a high amount of friction on the first two models of the 3.5 F and thus they could use a "normal" Compur shutters on both 3.5 F and 2.8 F size. The reason the 2.8 F came after the 3.5 F was that Compur did not supply the previous shutter (the one with the external planetary gears) in a size for the 2.8 F.

The third version of the 3.5 F used the differential gear system and along with the 2.8 F remained essentially unchanged for about 200,000 cameras, from 1960 to 1981.

Todd