>>> moonrise@telus.net 01/08/06 11:40 PM >>>
>>...
I realize that I should probably size the paper and that Lamp Black is
not
the best starting pigment, but I was just trying to get myself into the
ball
park on emulsion and exposure times. However, I'm stumped by the
negative
product...
Bruce Pollock<<
There you have it: size and use a different pigment. 20 minutes seems
excessive to me. With a quartz halogen 1000w 6 feet away my exposures
are around 6 minutes. In the sun more like 45-90 seconds. UV tubes are
about 6 minutes IIRC.
I'm not sure about comments of underexposure leading to reversal. I
believe it to be related to specific pigments. I've seen reversal shift
up and down the step wedge scale along with exposure but so far I've
only noticed its occurrance with certain pigments.
As others have noted try a lesser ratio of pigment to gum+sensitizer.
Your potassium dichromate should still be OK if it has been stored
properly.
Joe
Received on Mon Jan 9 12:43:32 2006
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