P3D RE: Olympus XA twin rigs, matching exposure

["Perry, Duane " <PerryD@xxxxxxxxxxxx>]

Gary Schacker wrote:> 
	> You can get EQUIVALENT exposures by adjusting the ASA settings but
the
	> cameras will still differ from each other
*	in their choice of shutter speed and aperture.  

Lets say I set one camera to ASA 100 and it selects f/11 and 1/125 and this
produces a properly exposed slide.  Then through experimentation I find that
the other camera must be set to ASA 200 to match the first slide.  Are you
saying that the second camera would select f/8 at 1/250 or f/16 at 1/60?  I
would think these cameras that adjust both f/stop and shutter speed would
have standard pairings of stop/shutter throughout their range except for the
bottom of the range where you hit the maximum opening of the lens and then
the shutter speed would just get slower with the lens wide open.   I am
still assuming blindly here that they go in steps (1/3 stop? ‡ stop?) and
you may be off one of those increments since the cameras and their views are
not identical.   A half stop difference in shutter speed or opening would
not seem to make much difference.  I see this as merely calibrating the
hardware of your exposure system, after that the "software" should be
identical.

Duane Perry


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