Re: istD test

[Robert Gonzalez]

I don't know what your trying to achieve.  If its in manual, then it 
wont meter except wide open if at all.  If you set the aperture to 
anything other than wide open, its going to stop down to that point when 
you snap the picture, but it will have calculated the exposure wrong. 
Shorting the A terminal would only be good in AV mode, and the aperture 
would have to be set on the body, since that's all it allows.  So my 
guess is your trying to get it to take an exposure in AV mode by both 
setting the aperture on the body and on the lens?  And setting it to "A" 
would allow that to work?  That might work.

Mark Roberts wrote:
Robert Gonzalez <[EMAIL PROTECTED]> wrote:


Mark Roberts wrote:

But what feedback does the body have to set the aperture to the correct 
setting?  I think he was talking about setting it to the "A" setting, in 
this case the highest aperture, then letting the body do the rest.
Well, that wouldn't work. I was talking about manual exposure.

Would that work still?  If the body thinks that the lens is in the A 
position, then it will attempt the stop down sequence to the "manual" 
aperture setting, which would be wrong. 


The camera would attempt to stop down to wrong position, but since the
camera would move its diaphragm lever *farther* than required, so the
lens' mechanism would stop it at the correct point. That is, if the
linear vs. geometric movement of the diaphragm lever is the way I think
it is.