Originally posted by kh1234567890 Yes. But if you're saying the lens sends these numbers...
focal length
aperture
...
SR focal length
I don't believe it because why in
1985 or whatever would there be a parameter called SR focal length? And actually, this SR focal length
cannot come from the lens. I just checked it on a 200mm lens M series lens. I had input 200mm as the focal length into the camera. It lists the SR focal length as...
204mm. Now where did it get that if the lens transmits absolutely no information? There's no option for 204mm. And 200mm is a possibility because I've gotten that with my Sigma 70-200 before.
So, I conclude that the SR focal length parameter is calculated by the camera from the actual focal length and....something else. But what? Clearly, the lens itself doesn't play a role in the process because if it did, we should get the same number for an M lens that the camera was told--or we'd get nothing at all and stabilization wouldn't work for pre-F series lenses. But it
does work. So...what on earth does the camera do to get this parameter?