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Kyoritsu

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Posted on Thursday, April 27, 2006 - 05:41 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Is there a specification for the run time difference between the first and second shutter curtains? Also, what exposure variation is acceptable/allowed across the frame?

I find that the run times of the first and shutter curtains are not constant with different shutter speed settings. Hence the exposure difference across the frame can be as high as 0.5 stop.
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Roberto Rossi

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Posted on Thursday, April 27, 2006 - 07:47 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

1/2 stop is the industry norm for most focal plane shutters. There are people who say they will adjust to 1/3 or 1/4 stop, but this is a bit pointless given the latitude of modern emulsions, tolerances in exposure meter calibration and tolerances in processing.
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charlie

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Posted on Friday, April 28, 2006 - 07:12 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

I agree with you that 1/2 stop difference from one side of the frame to the other does not sound good. Try having it repaired if it is a valuable camera.
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Kyoritsu

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Posted on Friday, April 28, 2006 - 05:20 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

I have heard from several professional repairers that 1/2 stop exposure variation across the frame is 'acceptable'. It sounds rather high to me.

I can achieve better than 1/4 stop variation across the frame for most shutter speeds, but not for the fastest shutter speeds.

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