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Re: [OM] Ilford EM10 Instructions? (slightly OT)

Subject: Re: [OM] Ilford EM10 Instructions? (slightly OT)
From: Joshua Putnam <josh@xxxxxxxxx>
Date: Fri, 08 Mar 2002 23:30:40 -0800
Chris Barker wrote:

Thomas

It is an exposure "meter" for black and white printing purposes. It is called a "monitor", I think, because it helps you to achieve consistency of exposure rather than an ideal exposure.

It has a sensor, 3 lights (green, low red and high red) and a graduated dial. It is the dial that confuses me: what is the basis for setting it?


There are various ways to use the EM-10. I'll describe how I use it.

First, you need a known-good exposure for your test print. It
doesn't much matter what that exposure is, you just have to know
that it makes the blacks black and the whites white. Let's say
for example that it's a 30 second exposure at some aperture.

Now, pick a spot on the negative that is the intensity of light
that corresponds to pure black on the print. Stick the meter in
that area and turn the knob until the green LED lights up. Write
down the number for that setting. Let's say it's 65.

Now you know that with that particular paper, under that
particular set of contrast filters, any time you want to make a
print, you get your image composed at the size you like, set the
dial to 65, stick the sensor in a part of the image that you want
to be black, and adjust the lens aperture until the green LED
lights up. When that LED turns green, it means the light is the
right intensity to make a black exposure on the print in 30 seconds.

You've now set the exposure for the blacks, the lightest part of
the negative. You make a print, and the blacks will definitely be
black. Whether or not the whites are white depends on the
contrast of the negative compared to the contrast of the paper,
of course.

That much is pretty much what I remember from the EM-10 manual.
(I actually do have the manual, but it's deep in the back of a
storage locker.)

Sometimes, though, you don't care as much about the blackest
blacks as you do about, say, open sky, or skin tones. You can
repeat the same process over again, measuring the light intensity
for those exposures instead.

I have a little table that I use. The vertical axis is the
contrast filtration that I use with that particular paper. The
horizontal axis is the type of exposure I want to measure. Each
box has the time and EM-10 dial reading for that zone. So if I
want to print a portrait at grade 4.5 filtration, I go to the row
for 4.5 contrast and the column for middle-of-the-forehead skin
tone, and I find the length of the exposure and the number I
should set on the EM-10 dial. For combinations I use a lot, I'll have exposures for black, 18 0ray, and several shades of skin.

Sometimes I have several options listed, meter settings for, say,
20 seconds, 60 seconds, and 3 minutes. That way there's almost
always one combination that's achievable whether I'm making a 3x5
print or a 16x20.

Some caveats:

The EM-10 doesn't seem to have very good voltage regulation, so make sure your battery is fresh.

The sensor can be thrown off by exposure to bright light. Turn it off and put it in a cupboard or drawer before turning on the room lights.

The sensor's color response isn't at all linear, so you really do need to have different calibrations for each set of contrast filters if you want to use the meter with them. You could just calibrate it for whatever grade you use the most, and do the conversion to other grades manually.

--
          josh@xxxxxxxxx is Joshua Putnam
            http://www.phred.org/~josh/
        Braze your own bicycle frames.  See
    http://www.phred.org/~josh/build/build.html


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