There was an article in Photo Techniques magazine within the last few years by Carl Weese, which described the use of pyro (I forget which formula) to process negatives that could be used to make both pt/pd and "normal" prints.
There was an article in Photo Techniques magazine within the last few years by Carl Weese, which described the use of pyro (I forget which formula) to process negatives that could be used to make both pt/pd and "normal" prints.
Brian Ellis
Before you criticize someone, walk a mile in their shoes. That way when you do criticize them you'll be
a mile away and you'll have their shoes.
The article to which Brian alludes is included in The New Platinum Print by Sullivan and Weese.
>>>Thank you so much. Now I need the lens and I am on my way.
Hey, no need to wait. Just use a pinhole while you figure out which lens you want.
I don't quite understand Clay's meaning of not more "overall density" but a "higher density range." Am I missing something? You push the density higher on the curve through exposure, you get more density. A denser negative overall. You process longer and you get more contrast. Because of Pt/Pd's inherent flatness you need a more contraty negative and because of the light sources inherent intensity relative to the materials sensitivity, you need more density to keep the shadows from blocking up. If I am mistaken then I will learn something new. But this is what the literature states so I need further clarification on these points. Thanks.
What I mean is that having extra dense shadow areas on the negative does nothing but add printing time to pt/pd printing. What you need is a good RANGE of densities, from the shadows to the highlights. For pure DOP palladium, a target density range of 1.7 is a pretty good bet. The process can handle up to about a 2.1 density range on some papers (such as Rives BFK). The shadow 'blocking' you are talking about is really just low shadow contrast, and can occur on some films (such as the Tri-X Sandy mentioned) that have really long toe sections. For these films, it may be necessary to overexpose slightly to push the shadows up onto the straight line portion of the film curve. For instance, my normal EI for Tri-X is 200. But that is true for my negatives being processed for silver gelatin as well.
Where you can get into trouble with intentionally overexposing by a stop or more and then overdeveloping on top of that is with films such as HP-5 or BPF200 that have a pronounced shoulder. If you have pushed your shadow density to about 0.7 (only 0.4 over b+f for this film), that leaves you only about 2.0 of density range in your negative even with the most aggressive development. A great deal of that will be flatter because of the shoulder, and thus lower contrast on the negative. This low contrast effect will be compounded with the inherently low contrast palladium toe. Tri-X, on the other hand, can give densities as high as 3.6, so an extra stop of exposure for that film normally means you will just be twiddling your thumbs a little longer during the printing. Keep in mind that an extra 0.3 of un-needed shadow density will turn a 10 minute printing time to a 20 minute printing time for palladium!
This 'running out of room' on your densities is one of the reasons for the use of proportional staining developers for UV processes like pt/pd. The stain adds extra effective printing density to the highlight areas, and lets you stay on the more linear part of the film curve, without pushing the films silver density beyond what it is capable of producing. For reference, check out Sandy's great article at www.unblinkingeye.com
As an aside, I find it amusing that several of the so-called 'old-style silver-rich' films cannot generate nearly the silver density that some of the newer (I guess by implication 'silver poor') tabular grain films are able to achieve.
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