At 08:17 PM 8/9/1999 +1000, Ross you wrote:
>After reading all of the messages recently relating to the vibration of an
>OM-1 with lenses >50mm when tripod mounted, even using the mirror lockup, I
>am left wondering how good the OM-3 & 3Ti are in this regard. They have
>neither mirror lockup or mirror & aperture prefire. (For that matter
>neither does the OM-2/2n). Does this mean that the full potential of the
>longer/bulkier Zuiko lenses can not be realised with these cameras when
>used on a tripod?
I think it can be realized with telephoto lens support and/or proper
shooting technique such as hand dampening and using one's finger to release
the shutter rather than a cable release. It depends entirely on the shutter
setting, of course. The vulnerable speeds are 1/2 to 1/30.
>What about the OM-4/Ti when prefire is not practical, eg macro shots
>waiting for a lull in the breeze. With the extra magnification of a macro
>setup, the shutter/aperture vibration with a lens like the 90mm would
>surely be pronounced.
Yeah, this is tough. The OM-4Ti shutter is smooth though, so using hand
dampening and finger release at the scary shutter speeds I think is the
best plan. Any mirror lockup scenario seems to me to be applicable only in
dead still settings.
>It seems that for tripod mounted photography with lenses longer than 50mm,
>if one is doing critical work for enlargement, the OM-4/Ti or OM2000 using
>prefire are the only real choices. I had one day aspired to own a 3Ti if
>some ever hit the second hand market at affordable prices, but maybe I'd be
>better just sticking to the 4/4Ti.
To summarize the problems: MLU on the OM-1 does not nullify vibration at
critical speeds because it isn't the source of the problem, which is either
caused by aperture stopdown or the horizontal shutter. The timer/MLU on the
OM-2S/4T could improve stability because it nullifies aperture stopdown
vibration, or the shutter might have been improved.
I sort of theorize that it's the latter. I'd guess that the electronic
"driver" on the OM-2S/4T shutter is smoother than the mechanical
counterpart of the OM-1. Can't say as to the OM-3(T) since I don't know
how it compares to the OM-1.
I also wonder whether NOT using MLU with the OM-1 at the critical shutter
speeds but instead using telephoto lens support where one can and good hand
dampening and finger release techique isn't the proper way to go.
Specifically, I wonder whether the synergy of mirror "slap", aperture
stopdown, and shutter release might not produce a better result than one
gets from removing one of these elements.
I would be fun to have a special ADITL dedicated to Olympus mechanical
Iowa City, Iowa USA
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