Lenses for Ap-priority AE

[pbasswil]

Hi all,

A basic question from a newbie:

In order for an aperture-priority AE camera (M7, Bessa R2/3A, Z.Ikon) to pick a shutter speed, it has to know what ap the lens is set to, right?
Do all M-mount lenses convey this info to the camera? Or only ones built after the earliest Leica M in-camera meters?

What about LSM (LTM) lenses with adapters? Can ap-priority AE ever be used with them?

Thanks in advance.

 

[ferider]

Welcome.

Non of the M/LTM lenses are coupled to the camera to "communicate" aperture information. The camera only "knows" via light measurement and ISO setting.

In contrast to most modern SLRs, you actually close down an M/LTM lens aperture when choosing an aperture. Which means the light arriving at the light meter is reduced.

Best,

Roland.

 

[pbasswil]

Rolland and Richard,

Ok, that makes perfect sense, (although I had to think hard for a minute)! It's hard to deprogram one's SLR assumptions.

Well that's really good news for me. Any glass I can manage to lock, duct-tape or screw on, is going to be good for AE. :^)

You got the bass thing right, Richard, although the name's Peter Wilson. "pbasswil" evolved out of an effort to find a reasonably compact hotmail name that hadn't been taken; I stuck bass in since I'm a bass player -- although I haven't touched a Fender Precision in quite a few years.

Thanks for the quick answers, and the warm welcome!