[Leica] Using M (and R) glass on a Sony NEX-7

[cummer at netvigator.com (H&E Cummer)]

Date: Sat, 9 Jun 2012 16:13:38 -0600
From: Bill Nelsch <photobynelsch at gmail.com>
Subject: Re: [Leica] Using M (and R) glass on a Sony NEX-7
To: Leica Users Group <lug at leica-users.org>

I have a stupid question:  When you say the D7000 is "linear" - what does
that mean actually?  How does that affect the exposure?

Bill in Denver

Hi Bill,
By linear I mean that as you close down the lens aperture the shutter speed 
drops by an equal amount in terms of light transmission
If you are at f5.6 and 1/500 and then close down to f8.0 the shutter speed 
adjusts to 1/250 - to f11.0 the shutter speed drops to 1/125
keeping the light transmission the same. That's what happens on the Nikon. 
On the Canon without Canon lenses that "talk" to the body
as you close down a Leica R lens mounted with an adapter that isn't chipped 
the shutter speeds drift away from the above response and you get more and 
more exposure variation.
Hope this clarifies my point for you.
Cheers
Howard