Perhaps other list members have experienced what I describe below and might be
able to offer some useful comments and opinions.
My OM4T has just been returned by the Canadian Olympus service / repair
facility in Toronto after a thorough CLA and shakedown. I have been assured
that shutter speeds have been calibrated to Olympus standards, etc, etc.
I am confused as to the accuracy of the shutter speeds or at least the shutter
speeds I see through the viewfinder. Before being sent in for service there was
always a very close approximation between incident light readings taken with my
Sekonic L508, spot readings taken off a gray card with the same meter, spot
readings taken with the OM4T off the same gray card, and the average reading
after taking several multi-spot readings with the OM4T through the viewfinder
so as to approximate 18% middle gray. Almost invariably the approximation was
within half a stop or less and as a final check it invariably accorded with the
"sunny 16" rule given the state of the ambient light.
Since the camera has been serviced, the meter readings in the viewfinder,
whether the average of several multi-spot readings or in auto mode, are showing
generally one and half stops over exposure as compared to readings with my
Sekonic whether off a gray card or in incident mode. This is disturbing and
doubly so since I shoot mainly slide film where the exposure latitude is less
than plus / minus half a stop.
I have just collected seven rolls of slide film [Ektachrome E100GX and Provia
100F] from a professional lab wherein I exposed numerous duplicates using the
OM4T's multi-spot metering function alone and then setting the camera to manual
and using the exposure shown by my Sekonic in incident mode. In all those cases
the incident readings set on camera were the same one and a half stops under
exposed as compared to the camera's measurements as seen in the viewfinder.
I now find myself in the odd position of discovering that the multi-spot
metered exposures are virtually perfect whereas the manually set exposures
based on the Sekonic's incident reading are between one and two stops under
exposed.
The Sekonic's incident readings along with its spot meter reading off a gray
card are virtually identical [ + / - 1/3 stop] and accorded with the sunny 16
rule so I feel comfortable that the Sekonic is accurate. As a further check on
this meter's accuracy I have a roll of Provia 100F shot in a Leica M3 using
90/2.8 and 50/2 lenses where I used the Sekonic's incident reading in all
cases. Those slides are properly exposed to within + / - 1/4 stop or so my eyes
judge.
Thus, I am left with a hand held meter that by all accounts is accurate and TTL
metering in my OM4T that shows ~ 1 1/2 stops over exposure in the viewfinder as
compared to the Sekonic and yet produces ideally exposed slides! For all seven
rolls of film I made doubly certain that the plus / minus exposure compensation
dial was set to zero and that the film speed was correctly set on the ISO dial.
Where I used a circular polarizer I increased the Sekonic's indicated exposure
by 1 1/3 stops. Again, I was still having the camera TTL meter showing me to be
1 1/2 under exposed.
As for lenses used, the great majority were taken with a 35-80 / 2.8 Zuiko
zoom, and the others with 24 / 2.8 and 85 / 2 Zuikos. There is no evidence to
suggest that the indicated aperture on any lens is inaccurate. The under / over
exposure issue prevails regardless of lens used.
Any and all opinions and comments will be greatly appreciated. I am in the
position of having to ditch my Sekonic so as to get perfect exposures with my
OM4T knowing that the indicated exposures in the viewfinder are seemingly
incorrect, and yet keeping it close at hand if I use my old rangefinder!
John Hudson
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