NetNews Usenet Archive 1992 #27/NN_1992_27.iso/spool/rec/photo/20346

Internet Message Format | 1992-11-23 | 1.9 KB

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From: [e-mail] (Michael C. Adler)
Newsgroups: rec.photo
Subject: Contrast mask woes
Message-ID: <[e-mail]>
Date: 23 Nov 92 16:39:46 GMT
Sender: [e-mail]
Reply-To: [e-mail] (Michael C. Adler)
Organization: Digital Equipment Corporation
Lines: 31


I tried to make a contrast mask this weekend for a 35mm transparency and
now have a question.  The scene was essentially a black and white image
(though taken on Kodachrome) of a deep black volcanic peak with patches
of snow as well as very puffy clouds behind it.  There is about a 5 stop
difference between the detail in the clouds and the detail in the mountain
and the actual detail within each object covers about 1 stop in each range.
Your basic printing nightmare.

It just so happens that dodging would work perfectly well for this image
since the two separate exposure areas are rather easily separated but I
wanted to try using a contrast mask to find out what the effect would be.

I made a mask that seemed about the minimum density to make the image
printable without dodging.  I wouldn't say the cloud region was especially
dark.  The mask had relatively low but perceptible detail (developed about
1/3 of normal) and was unsharp.  When I laid the mask over the slide a miracle
occurred:  the subtle detail in the clouds disappeared completely.  The mask
compensated perfectly for the original and generated a very nice gray.

I don't believe using an intermediate highlight mask would have worked since
the detail was too subtle.  I'm also not convinced that I can make a mask
with much less contrast (perhaps I'm wrong).

I was using 35mm FP4+ for masking film and used Ilfotech-HC 1:31 to develop
it for 2 minutes at 68 deg. F.

Any suggestions on what I could do differently?

Thank you,
-Michael