Hi John, you are right about the shutter adjustment, the two turning
positions under the md switch is to balance the left and right exposure. I
did shutter measurement not only at the center but also at extreme left and
right (the higher the speed the more critical).
In my experience for OM-1(n), the shutter speed can usually be
corrected/balanced by slightly adjust the two positions (increase the
tensions due to curtain strings loosing with age?). For OM-1(n) there is a
"disc" under the mirror box for adjusting of each individual speed but I
found it seldom necessary.
The high shutter speeds (1/500 and 1/1000) of OM-1/2 are much slower (~0.5
stop or more) when operates with MD (may be winder also).
C.H.Ling
----- Original Message -----
From: "John Hermanson" <omtech1@xxxxxxxxxxx>
To: <olympus@xxxxxxxxxxxxxxxxx>
Sent: Thursday, July 07, 2011 10:54 PM
Subject: Re: [OM] a flower?, or Zuiko 300mm 4,5 bokeh
>I see a lot of OMs in which high speeds have been "adjusted" by turning
> the curtain speed settings visible under the md switch. WRONG.
> Curtains must go across the film plane at the same speed. All this will
> do (depending on how much info is given by the shutter tester) will make
> user think high speeds are correct when they are really only correct in
> the center of the frame. Underexposure on opening side, good in the
> center, overexposure on the closing side. Or vice versa depending on
> which curtain is sped up or slowed down. Adjusting high speeds are done
> elsewhere.
>
> Shutter speeds when fired with motor drive or winder may be slightly
> faster than when fired by hand. Same applies when mirror is locked up
> in OM-1/1N. High speeds are slightly faster (or slower, don't remember).
>
--
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