Drydown and other esoteric mysteries

["Tom none Jarana" <oh.yes@xxxxxxxxxxxx>]

I've recently heard some comments on this grapevine suggesting that DRYDOWN has something to do with "experience and practice".  Nonsense!  It is basic physical science.  As the emulsion dries it shrinks, the grain compresses, and this results in an unwanted increase in print density.  To determine the "DRYDOWN FACTOR", for a given paper, just do this:  Make a print that looks exactly the way you like it 'when it is wet'. Mark the back of the print "standard". Now make 5 more prints reducing the exposure TIME 2% on each of the suceeding prints, and write on the back of each print 2%,4%,6%,8%,10%.  (Example: if your perfect wet print was exposed for 10 seconds, then print 2% would be exposed for 9.8 seconds, print 4% would be exposed for 9.6 seconds, print 6% would be exposed for 9.4 seconds, etc.) Batch Develop, fix, and wash all the % prints together for the same time.  Then dry all the % prints. Leave the print marked "STANDARD", in the water. Compare the dry prints with the!
 wet print. Find the one that matches exactly, turn it over and read your "DRYDOWN FACTOR" for that paper. There is no esoteric mystery about drydown. My findings, (using a non hardening fixer) are as follows:
Ilford MGFB IV  4.5%
Ilford MGIV RC  9%
Oriental VCFB   4.5%
Oriental VC RC  4.5%

Expired paper will of course dry-down darker. (Expired paper should be thrown away or given to someone you don't like)  



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