Luis Nadeau (nadeaul@nbnet.nb.ca)
Tue, 16 Mar 1999 19:28:14 -0400
At 5:33 PM -0400 99/3/16, Sandy King wrote:
>For reasons which I don't fully understood, but have commented about
>previoulsy, in my working conditions I routinely require much weaker
>sensitizer than those recommended in most of the literature. This in spite
>of the fact that I have worked with a number of different gelatins and
>dichromate solutions, and always make tissue and sensitizers with distilled
>water. To give you an idea, these are the typical strength sensitizer
>needed for negatives of a given density range.
>
>DR .8 - 1.0 1/8%
>DR 1.0-1.2 1/4%
>DR 1.2-1.5 1/2%
>DR 1.5-1.8 1%
>DR 1.8-2.2 2%
>DR 2.3+ 3% and up
>
>I have not experienced any uneven sensitizing with these very weak
>sensitizer, and I don't do anything special. I sensitize by soaking in an
>open tray for 2.5 minutes, then squeegee out the excess dichromate
>(emulsion side down) on a clean sheet of plate glass, and place the tissue
>on a drying rack to dry. Drying is accelerated by directing the air from a
>fan a close distance over the surface of the tissue.
>
>I am currently printing with 350na BL fluorescent tubes. For a couple of
>years I used GE Daylight tubes, which required an approximate 2X increase
>in sensitizer strength to give the same contrast.
With the same strength it provided more or less contrast?
What about the speed? What distance away from the printing frame?
Luis Nadeau
NADEAUL@NBNET.NB.CA
Fredericton, New Brunswick, Canada
http://www3.nbnet.nb.ca/nadeaul/
This archive was generated by hypermail 2.0b3 on Sat Nov 06 1999 - 10:09:03