Graphic Arts films

I said to Philippe that I would search for my data, which I haven't
succeeded...

But I have just tried compared Kodak Kodalith ortho film 6556, type 3
in 35mm 100 feet roll (expired June 2000) against Arista APH 5x7
sheet. I haven't done the densitometry for reading Dmax yet, but
using DS-10 (formula to follow) at 20C for 5 minutes with continual
agitation (the idea is to see the maximum contrast the material gives
in this developer), 6556 has lower contrast (records at least 19 steps
out of 21 steps of Stouffer TP35C but APH seems to record about half
the number of exposure range. APH develops faster, but the speed is
1.5 stops lower using non-color corrected enlarger light, based on 0.1
log density above base+fog criterion on whatever the contrast I
got. If APH could be developed for comparable average gradient to that
of Kodalith, its speed would be even lower.

The developer is a phenidone-ascorbate type buffered at pH of 8.00,
originally designed for continuous tone films. The base+fog of both
films was a bit high (both 0.15), but this might have something to do
with the developer formula (no antifoggant or restrainer).

Anyway, what I wanted to say is that Kodalith records wider range of
exposure if processed in a developer similar to XTOL (stock). Kodalith
is more susceptible to halation though its probably better suited for
pictorial grade in-camera exposure.

--
Ryuji Suzuki
"Reality has always had too many heads." (Bob Dylan, Cold Irons Bound, 1997)