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Re: [OM] Help with OM-PC problem

Subject: Re: [OM] Help with OM-PC problem
From: HI100@xxxxxxx
Date: Wed, 22 May 2002 00:55:49 EDT
Cc: dreammoose@xxxxxxxxx
>>
Does the Program Mode work properly with non Zuiko lenses? Setting the 
aperture accurately depends on a rather accurate relationship between 
the location of the stop-down lever and f-stop. The manual cautions 
about this, but I'm looking for practical experience.

The manual says the shutter speed may vary by no more than one stop from 
the viewfinder indication with the 50/1.2 &1.4 and the 75-150 & 35-105 
zooms. I assume this is because the stop-down levers on these lenses 
vary from standard. They say proper exposure is still assured. I can see 
how this would be true in OTF mode, but it appears ESP mode sets a fixed 
speed before firing the shutter and so can't compensate for inaccuracies 
in mechanical f-stop setting. Or does it stop down before determining 
the final shutter speed?
Obscure stuff, but maybe somebody on the list knows.
<<
Moose,
           Some of the Olympus service info for the 2S addresses this partly 
and discusses which OM lenses are not recommended for program mode.  Some of 
the lenses have a longer aperture settling time or bounce etc. depending on 
design and coupling mechanism/springs etc.  I made a post on this a very long 
time ago which should be in the archives. I seem to remember the variance in 
speed could be more like 2 stops under some combinations. 

Third party lenses could have longer settle times or different stop down 
positions. This could lead to not setting the same aperture that the camera 
thinks it is setting because of lever positional difference

I have no insight on ESP mode except that it could still be auto OTF if the 
correction is effectively like dialing in a sensitivity correction (like a 
different ASA) to normal auto/PGM mode. 

Regards,
Tim Hughes
Hi100@xxxxxxx


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