[APML] B&W film tests

[George Anderson <georgea@cam.org>]

Well it is back to square one and I will be re-testing some of the films
that I have already tested.
I decided to have a look at T-Max 400 and see how it handled hypering.
Before starting the testing I did a google on Tmax 400 and hypering.
Back in '97 Bard Wallis commented on the list that hypered T-Max 400 was
slower than hypered TP.
I e-mailed Brad asking if he still had any details on his hypering time
etc.
Brad came back with a response of 30 minutes in hydrogen at 40C.
I did a quick comparison of pure hydrogen hypering times for TP versus
the time that I require using forming gas with my rig and found that his
10 hours for TP and my ~75hours gave a 1:7.5 ratio.
Using this as a rough guide it would seem that T-Max would require 3.75
hours in the cooker after dessicating.
Since my previous tests started with 10 hours I have decided that I may
have overcooked the films and been on the heavy downslope with over two
times the required hypering.
I will now re-do some of the films with two hour incremental hyperings.
At the moment I have HP5+, Delta-400, and TMY-400 drying in the tank.
I'll see how the two Ilford films fare at lower hypering times before I
waste any more money on SFX-200. I have benchmarked two of the three
films out of the box (due to an error the Delta-400 benchmark didn't
turn out but will be repeated later with another roll) and will compare
the results with the incremental 2 hour hyperings.
On the plus side my 150' roll of TP and three bags of D-19 came in
today.
And on the colour side, as a lark I have ordered 10 rolls of "China
Lucky 200" film. The manufacturers website shows excellent red response
and claims good reciprocity characteristics. At $1.20 a roll I figure it
is worth a shot.

George Anderson
Montreal Canada

Clear skies and good health
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