RE: Speed Point in PT/PD printing?

From: Eric Neilsen ^lt;e.neilsen@worldnet.att.net>
Date: 11/10/03-07:21:33 PM Z
Message-id: <000701c3a7f2$29584200$0100a8c0@NEWDELL>

Sandy, The data that I was referring to is on Page 15 of Vol. 34, 1986 of
the Journal of Photographic Sciences. I was mistaken, he includes
wavelengths down to 254nm and up to 620nm in a table giving Quantum Yields
for the Photolysis of Aqueous [Fe(c2o4)3]3-.

I would recommend that you try several "brands" of Ferric powder to check
the 25% solution. If you mix B&S powder, or any powder for that matter, the
best you can hope for is a 25% solution from that powder as the ferric does
vary from maker to maker and batch to batch. I have seen speed variations
of +/- 10% when switching batches of ferric powder.

Are you mentioning glass or other UV blockers within the test?

Eric Neilsen Photography
4101 Commerce Street
Suite 9
Dallas, TX 75226
http://e.neilsen.home.att.net
http://ericneilsenphotography.com
 

> >> >> >>Any thoughts on this by pt/pd printers would be appreciated.
> >> >> >>
> >> >> >>Sandy King
>
Received on Wed Nov 12 16:07:55 2003

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