From: Scott Wainer (smwbmp@starpower.net)
Date: 04/10/03-08:20:21 PM Z
Hi all,
I would just like to thank everyone that responded to my post.
I believe that I found the answer to my problem. Thinking it strange that I
was getting no information below zone III, even with up to 30 minutes in the
developer, I went back and started from scratch. What I found was that I had
made a careless mistake (a brain-fart; if you will) in calculating the
dilution of the developer.
According to published data, Ilford FP4+, rated at EI 160, developed in
FX-37 diluted 1+3 for 4.5 minutes at 68F/20C will result in a negative that
prints well on grade 3 silver gelatin papers. By increasing the dilution to
1+5 and adding 50-100% to the development time, it is, according to Crawley,
possible to uprate film speed by up to 4x. I decided to test the 1+5
dilution and somehow, instead of diluting the developer 1+5, I ended up
diluting it 1+12.
After testing the film again, this time using the correct 1+5 dilution, I
found that my personal EI was 80. I now have a zone I reading of 0.12 above
fb+f and a zone VIII reading of 1.22; giving me a contrast range of 1.10. To
test further, I shot a roll, at EI 80, in my backyard and the negatives look
good though I have not printed them yet.
Taking into account information found at the link
(http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=000EYy) Liam provided
and my own testing, it seems that Arista Pro 125 is most likely Ilford Pan
F+. Under controlled testing, published data states that Ilford Pan F+,
developed in FX-37 diluted 1+3 for 4 minutes at 68F/20C, should have an EI
of 80. If diluting FX-37 1+5 does give at least a 1 stop increase in speed,
and my equipment and processing are off by 1/2 - 2/3 of a stop, then my
testing would seem to support the idea that Arista Pro 125 is actually
Ilford Pan F+. What I don't understand is how the seller and manufacturer
can mislable and misrepresent the product.
Thanks again to everybody,
Scott
smwbmp@starpower.net
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