ClassicVW@xxxxxxx writes:
<< I know you weren't here for the complete thread, but before we run the
risk
of branding the PROGRAM mode cameras as "not being able to work with all
lenses", OR that "Even Zuiko lenses don't work on al Olympus OMs" ..... Are
we now talking about the "warning" Olympus gave with reference to
third-party
lenses, or are we talking about motor-drive capability?
>>
George,
I was expanding a bit on other people's comments regarding the
warnings given by Olympus on using OM lenses as well as third party lenses in
Program mode. Most of what I said was based directly on Olympus's own
documents regarding issues involved with using OM lenses in Program mode. My
comment was not specifically in regard to the retard mechanism added to allow
program mode to be added which slows MD operation. The Olympus provided data
I listed, illustrates that even with the most generic OM lens the 50mm/F1.8,
the Olympus acceptance criteria allow about 1 stop or so error in programmed
aperture setting, although overall accuracy of exposure is good ~0.4EV. Some
other OM lenses apparently cannot set maximum aperture in PGM mode. Neither
of these is a big deal provided the normal OTF measurements finally corrects
the exposure, except that the exposure time may get long for handholding.
(e.g. 1/60-> 1/30) I was really replying to what somebody else had asked :
what sort of accuracy could you expect in the aperture setting.
My other comments related to how the stop down mechanism works because
somebody else had made the assumption that it relies on a calibrated pin
position versus aperture setting, which it does not. This is advantageous for
use with 3rd party lenses which don't have to match OM lenses exactly then.
I also listed specific OM lenses Olympus said do not give correct overall
exposures in PGM mode because of aperture construction (bounce etc) . This is
a bigger deal than inaccuracy of aperture setting which gets corrected by
the OTF fine correction of exposure time. Olympus also said these lenses gave
the biggest problem when it was trying to set high shutter speeds. This is a
problem because with large lenses ( like most of those listed) you most often
want to run high speeds to minmize handshake.
Sorry if my post was confusing.
Regards,
Tim Hughes
>>Hi100@xxxxxxx<<
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