One can not simply transfer the "tonal range" of a film matched to silver
gelatin to platinum. The curves are very different. For ME, I want good
separation in my platinum highlights, and the highlights on a "typical"
platinum negative (classic Ferric Oxalate process platinum) are way beyond
what the silver gelatin worker cares about. The silver gelatin worker
would call these highlights zone 9, 10, 11. The platinum worker calls them
zone 7 or 8. Tri-X and HC-110 gently compresses the highlights for the
silver gelatin worker, allowing a more pleasant, softer feel. If the
platinum worker needs 3 or 4 zones beyond this compression.....
Try a modern "strait line" film (T-Max, HP-5, or FP-4). They may not be
your favorite silver gelatin film, but that doesn't mean they won't be your
favorite platinum film! Actually I like HC-110 a lot. My favorite
Platinum combination (for in camera exposures) is T-Max 400 and HC-110. I
just wish they made T-Max 400 in 11x14 :-(
One last, and possibly contentious, comment. If you are shooting small
format originals, for later enlargement to platinum negatives, and are
shooting in low to mid contrast situations: you may find yourself happier
shooting color E-6 transparency film as the original! This leaves you only
one generation removed from the final negative, rather that 2 with normal
practices. This difference may be (IS in my experience) far more important
than the curve of the original film. Just be sure to enlarge onto a
panchromatic film.
tomf2468@pipeline.com (Tom Ferguson)
>> Well, because I cannot afford a large format camera yet. I am building my
>> own slowly, piece after piece. But I plan to use 35mm tri-X shots for alt
>> processes. What is seducing in tri-X of course is its tonal range, and I
>> wondered if it would better suit to platinotypy, just for that reason.
>> I noticed that one may have huge grain differences when processing tri-X
>> with different developpers.
>> Maybe some old recipes with slow developpers could suit for finer grain ?
>>
>> Thanks for your mail
>>
>> Philippe Monnoyer
>>
>The beauty of the tri-x/HC110 combination is the evenness of the tone
>spacing from deep shadow to highlight. Arnold Gassen's "Handbook for
>Contemporary Photography" has a series of parametric curves which
>illustrates this quality quite clearly as compared to other film/developer
>combinations. Given the inherent "softness" of the Pt/Pd process, I wonder
>how large you are going to have the grain "objectionable". Fine grain
>developers, usually incorporating silver solvents to soften the grain
>edges (resulting in smaller grain size) usually loose sharpness as a
>result.
>John