Dumb question re: adapters

[froyd]

Am I correct in assuming that if I use a screw mount adapter on a Bessa R#a, I will lose AE? Are some of the adapters coupled so the lens can communicate to the body what aperture it is using?

 

[Will]

Am I correct in assuming that if I use a screw mount adapter on a Bessa R#a, I will lose AE? Are some of the adapters coupled so the lens can communicate to the body what aperture it is using?

No it won't.

RF don't use open aperture meter, so lense do not coupled to the meter like a SLR does..

 

[payasam]

Froyd, unlike SLRs' lenses, which are ordinarily at full aperture for focussing and must communicate full aperture (and sometimes set aperture too) to the body, the lens of an aperture priority RFDR is always at taking aperture when you work in automatic mode. Notice that there are no shutter priority RFDR models which stop the lens down when the shutter fires. Uncoupled lenses, therefore uncoupled adapters. The only coupling is through the amount of light that the lens passes, and that is not mechanical.

 

[ClaremontPhoto]

The adaptor is just a that, it adapts a Leica thread mount mount lens to a Leica M bayonet mount camera. No more no less.

You still get the AE, because the exposure meter measures the light entering the camera. The adaptor makes no difference to that.

None of the adaptors communicates aperture. None of the lenses do either. The system doesn't 'know' the aperture, it just meaures the light and varies the shutter speed to suit.

[Edit: the previous two replies were not there when I read the original question. They only appeared later after I replied.]