Re: First Gum Print

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FotoDave@aol.com
Date: 03/08/03-01:04:46 PM Z


It still doesn't sound like overexposure to me. Remember Dmax of 1.26 means
approximately 18 times exposure from your Dmin (10 to the power of 1.26), so
even if your ideal exposure time is 5 minutes, then it would take 90 (= 5 x
18) minutes before you get to that complete black.

Or working backward, if exposing 25 minutes give you that nice full black, it
means that for dmin, an exposure of 25/18 = 1.4 minutes is enough to give you
that nice black (of course monitor viewing might cause the difference, but
your black looks very nice).

It looks to me like your emulsion is fogged by light or chemical, or you
forgot to mix in the gum (I one time use straight gouache and dichromate
without adding gum, the black was beautiful, and the image was exactly yours
except perhaps the border), so my conclusion was the gum in gouache paints
are hardened somewhat.

Dave S

> Hmm. I thought you had used 24% dichromate. I really think what I have is
> an overexposure.


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