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From: jib@prism.UUCP
Newsgroups: net.rec.photo
Subject: Re: Orphaned Response
Message-ID: <11200007@prism.UUCP>
Date: Tue, 25-Jun-85 12:06:00 EDT
Article-I.D.: prism.11200007
Posted: Tue Jun 25 12:06:00 1985
Date-Received: Mon, 1-Jul-85 06:50:58 EDT
References: <2046@watcgl.UUCP>
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Nf-ID: #R:watcgl:-204600:prism:11200007:177600:1377
Nf-From: prism!jib    Jun 25 12:06:00 1985


/* Written 10:30 pm  Jun 16, 1985 by jer@peora in prism:net.rec.photo */
> I have a question about this off-the-film metering... how does it work?
> Don't different films reflect different amounts of light, and in different
> colors?  E.g., of the films I regularly use, one is a dark buff color, one
> is a very light blue, and one is a sickly pink.  Wouldnt the kind of film
> you use thus have an effect on the metering?
> 
> Now, don't misunderstand; I'm not saying "I don't believe it will work,"
> apparently it does... I'm just curious how!
/* End of text from prism:net.rec.photo */

I've had an OM2 and an OM4 -- both with OTF metering for several years.
Apparently the average reflectance of most films is about the same.
By the way, at fast shutter speeds (> 1/60), the light is really measured
off a constant pattern on the back of the focal plane shutter.

Worth noting, however, is that Polaroid's instant transparency films are
much darker in color than standard film and DO NOT work in OTF mode.
And unfortunately, the amount that metering is off will vary depending on
the shutter speed (which determines how much of the film versus shutter
curtain the meter acutally reads).  On the OM-4 I use spot mode for this
film because the spot mode does not read off the film.  With flash, I have
to put the flash on manual or "non-OTF automatic" with Polaroid films.