Tom Ferguson (tomf2468@pipeline.com)
Tue, 06 Apr 1999 07:19:45 -0700
>From: Liam Lawless <lawless@vignette.freeserve.co.uk>
>
>The obvious answer about orange safelighting is that it depends on the
>intensity and the length of exposure <BIG SNIP>
>
>But continuous tone is different, and even a red safelight that is too
>bright/too close can cause problems <BIG SNIP>
>From: MMagid3005@aol.com
>
>I use an orange safelight about 8 feet away, shaded and pointed toward
>the opposite wall, and have had no fogging.
Let me add to the above comments on lith film and fogging problems in
enlarged negative work. With Freestyle APH I did get significant fogging in
an 8 x 11 foot (2.5 x 3.4 meter) room with two 15W orange safelights. One
safelight is perhaps 5 feet (1.5 meters) from the enlarger area, the second
dianginally across the room about 5 feet from the fix tray. The fog was
high enought to confuse my density range tests.
So, my advice is to test any safelight used with "con tone" lith film. I
would suggest giving the film a below "threashold" from enlarge exposure,
then covering partialy with a large coin (US quarter size), then exposing to
safelights for 1.5 times you maximum work time (a little safety, and a
compensation for "wet" time).
Remember that you biggest concern is fogging low (thin) values, not clear
film. Film takes a certain amount of energy to become active (cross it's
threshold). Once it's crossed, then a much smaller amount of safelight can
alter (harm) these low values.
Tom
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