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From: hkr4627@acf4.UUCP (Hedley K. J. Rainnie)
Newsgroups: net.rec.photo
Subject: Re: In-Camera meters  (Incident Vs. Reflective)
Message-ID: <2720004@acf4.UUCP>
Date: Sat, 23-Feb-85 14:12:00 EST
Article-I.D.: acf4.2720004
Posted: Sat Feb 23 14:12:00 1985
Date-Received: Wed, 27-Feb-85 05:58:50 EST
References: <364@wjvax.UUCP>
Organization: New York University
Lines: 37

Assuming that you are using a film with any sort of exposure latitude, you
should NOT adjust exposure due to the model's complexion.  If she has dark skin,
you do not want to increase exposure until her skin becomes lighter.  If you
are taking pictures of a white wall, you do not want to decrease exposure
until it looks the same as a black wall.  An in camera meter will attempt to
do this.

Reflected light is a component of at least two variables.  Light intensity
and reflectivity of the subject.  The in camera meter must guess at the
values of the components.  It does so by assuming that every object it 
photographs has precisely the reflectivity of an 18% grey card.  If the
subject has this same reflectivity, fine.  Otherwise, you will have to 
manually compensate... "Hmm does that green dress look a half stop or a full
stop brighter than 18% grey?"

As for the model being in shadow, the incident meter should be placed in the
same shadow as her face, thus yeilding accurate exposure.  Most incident
meters do average between shadow and highlight by way of a plastic bubble
over the sensor.  However, replacing the bubble with a disk and pointing it
alterately towards the lightsource and away will yeild accurate highlight
and shadow readings.

Though I am an amateur photographer, all of the professionals I have known
rely heavily on the incident light meter--so heavily that most admit that
they are completely helpless without it.

Now, I am not going to say for a moment you can get perfectly exposed shots
using any method unless we are being purely technical.  There may be times
when you want to under or overexpose a shot deliberately.  I happen to
feel that an incident light meter will give you a "technically correct"
exposure which you may then alter to suit your needs.

Incidentally:
The FM does not need an exposure lock since it is a completely manual camera.

Rei Shinozuka
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