Zeiss lenses for Contax/Yashica mount Problem with one piece

ic-racer said:

With the FX-3 (an open-aperture reading camera) the meter only needs to know how many stops down from full open. The actual numbers don't matter. It knows the wide open exposure (due to the TTL meter) and calculates from there.

Click to expand...

I got your point.


I said:
-) a indicator that tells the maximum aperture and a indicator that tells the preset aperture

-You said
-) a indicator that tells the difference from the preset aperture to the max. aperture.

So you deviate in two points from my approach.
-) not telling true apertures (neither the max. nor the preset one), but only the difference in stops between them.
-) by this only needing one actuator in place of two


But by this the system lacks the ability to show the preset aperture in the finder directly and to communicate with a simple autoexposure flash.

"The extra pin is for cameras that want to electronically display the aperture. "

Or for cameras that use some sort of automation such as aperture or shutter speed priority? My Topcon Unirex required me to input the max aperture, even though it had a viewfinder function just like the FX-3

I followed Rolleiflex during 1970s and 1980s. They went from one pin (aperture stop down metering) to two pin (wide open metering) to three pin (shows the aperture digitally in the viewfinder).
The 'third pin' was actually on the camera body, not the lens. It engaged with the base of the lens. the farther in the pin was pushed by the base of the lens, the larger number the maximum aperture. The system only worked to f1.4 (no f1.2).

The part the OP has removed indicates to the camera body the maximum aperture of the lens. Not all Contax/Yashica cameras have the aperture displayed in the viewfinder and those that don't, don't use this information. Yashica FX-3 and Contax S2 for instance.

The other aperture coupling between lens and body indicates the number of stops the lens has been stopped down from maximum. This is the only information required to calculate exposure in manual or aperture priority modes so the part in question won't affect the exposure. But in shutter priority and program modes, this information is used so exposure would be affected.

Yes Ic- racer I agree with your findings. I think without that metal piece a Fx-3 and S2b would work correctly. I believe also the Ax would work correctly, just displaying in the viewfinder 1,2 when you are working at 1,4 and so on. I think it can be some issue only when printing some aperture information from data back...
Well, shutter priority, yes could be also an issue. But I practically don't use it...except that I am planning to make some time lapse shots, there could be an issue...but I guess I can adjust the ISO setting to correct this error. Maybe rating a 100 asa as 64 asa.

I understand the inserting wire solution now, I tried but didn't work...