----- Original Message -----
From: "Bill Pearce" <bspearce@xxxxxxxxxxxxx>
To: <olympus@xxxxxxxxxxxxxxx>
Sent: Tuesday, 30 September, 2003 07:20 PM
Subject: [OM] John's metering dilema
> Most of you that have spent some time on this list know that I consider
the
> incident meter to be the gold standard in at least 900f metering
> situations. I am joined in this by virtually every commercial and
industrial
> shooter alive. The joy of the incident meter is that it compensates for
> various situations that the reflected meter cannot, the most obvious being
> highlight and shadow. The complex ttl meters in wonderbricks spend a lot
of
> time and trouble doing what the much more simple incident meter does
> automatically. This makes me totally confused by John's situation!
I had a lengthy phone call from "Mike" at Nortown Photo Service [authorized
Canadian Olympus service / repair station where my OM4T went for CLA] in
metro Toronto this morning.
He advised me that the TTL metering system and shutter speeds had been
accurately calibrated and set to original Olympus standards using Olympus
supplied or authorized equipment. He also advised me that there was no
comparison of the indicated output of those recalibrations with any other
metering devices such as a Sekonic meter. He told me that I should choose to
use one metering system or the other but not both! What seemed to go above
his head was that the end product of using either one of the two metering
systems, namely a properly developed negative or slide, should be
identically exposed regardless of which metering systems was used.
He tried to explain that the indicated metering differences between using
the Sekonic and the OM4T's TTL system resulted from the differences in the
colour temperature sensitivity of the light measuring cells in the two
meters. Whether there is any substance to this statement is something beyond
my knowledge and could perhaps be commented upon by others. My immediate
feeling is that this is a bit of a bogus argument in the present case.
What I think has happened is that the linkage between the exposure
information shown in the viewfinder does not match the actual shutter speed.
For example, multi-spot metering shows an average exposure in the view
finder of say 1/45 @ f16. When the shutter is fired the shutter actually
fires at 1/125 @ f16 giving me a properly exposed slide. When I set the
camera manually at 1/125 @ f16, which is the Sekonic reading, the shutter
actually fires at ~ 1/375 @ f16 giving me an under exposed image.
If my Sekonic gives me properly exposed slides using an M3 I am confident
that the meter is accurate. The fact that I cannot take my Sekonic's reading
to my OM4T in manual mode tells me that the link between OM4T's indicated
shutter speed is different from the actually speed with which the shutter
fires. How does one get that line of thinking over to the CLA people!
John Hudson
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