Archived posting to the Leica Users Group, 2002/01/13
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At 4:37 PM -0500 1/13/02, John Hicks wrote:
>At 11:10 AM 1/13/02 -0800, you wrote:
>
>> OTF flash automation doesn't work, of course
>
> It works with the OM cameras. I know Nikon's FP mode used to not do TTL
>auto but I have no idea about its current status.
> If Leica's going to do it I sure hope they do it "right" and not just the
>fairly useless non-TTL FP mode.
>
>John Hicks
>jhicks31@bellsouth.net
>
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You're right; Olympus does use a form of OTF flash measurement. It is
not quite the same as a regular OTF flash measurement, as the camera
cannot 'see OTF' what is about to be exposed by the film slit. It is
a combination of off-the-film and off-the-shutter-curtain like the
ambient measurements at high speeds. Regular OTF flash automation
actually measures off-the-film. That's probably why Nikon didn't
provide automation, as their camera metering system/curtain paint
would have had to have been modified.
For this to work, the curtains have to have a horizontal white or
grey stripe (for horizontally travelling shutters), not just a spot
on one curtain, and that to obtain centerweighted readings the sensor
optics have to focus on the center. If the M7 does allow this type of
OTF flash automation the metering pattern will change, most likely.
- --
* Henning J. Wulff
/|\ Wulff Photography & Design
/###\ mailto:henningw@archiphoto.com
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