Negative Contrast for Pt/Pd printing

[Mark_3632]

Hello.

I am getting into 5x7 for the sole purpose of creating platinum and palladium prints. I have shot 4x5 for years and have little problem creating a good negative to print from. I have read most of the how-to articles and books out there. God I love Inter-Library Loan. Any way, all say the same thing about the negative. Every book says the negative must be much contrastier than for silver printing. My question is this: Does the scene shot have to be contrasty to begin with or does the negative development at N+2 take care of that?

There is probably an easy explanation but I can't figure it out.

Thanks again in advance

[james mickelson]

The negative must be not only have more contrast but have more density. About a stop more density and two stops more contrast. And this also depends on what light source you will be employing to expose the print. UV tubes or sunlight. I would suggest you look for more info about the process which I am sure you will benefit from.

[Jorge Gasteazoro]

The density range of your negative should be in between 1.4 and 1.6. IOW if you substract the density of the shadows with detail from the density of the highlights with detail you should have at least a range of 1.4.

Even if the image is contrasty, you still have to give it additional development to fullfill the requirements for a pt/pd negative. The amount that you have to develop depends on the original scene. I recommend you read "platinum & Palladium printing" by Arentz and "Beyond the Zone SYstem" by Phil Davis for a better understanding.

For a quick try out I would say you are correct and your times for N+2 would become your N times for a pt/pd negative. As always is best to make some testing before you undertake printing pt/pd.

I would recommend you use a stainning developer like Pyrocat HD for better results. Good luck.

[clay harmon]

I must disagree that more overall density is needed, unless your idea of fun is standing by a UV box for hours waiting for a print to expose properly. What you need is a properly exposed negative where the density RANGE is higher. If you are planning on doing palladium printing, a density range of 1.7 is pretty good. This means that if shadowed areas have a negative density of 0.3, then highlights should be about 2.0. A typical negative intended for silver printing has an ideal density range of about 1.05, so the highlight density in that case would be about 1.35.

I see this well meaning advise to overexpose and overdevelop for platinum all the time, and it is just not right. On films with pronounced shoulders such as HP-5, all it does it guarantee that you will have pushed the highlights into the low contrast part of the shoulder and then endnn up printing it with the platinum low contrast paper toe! A recipe for muddy highlights, to be sure. Just make sure that you actually HAVE shadow density, and then increase your development time to make your highlights more dense. A good rule of thumb for non-staining developers is about a 50% time increase.

[William Marderness]

I use a density range of 1.7 for pt/pd negatives. Using N+2 development as normal should be about right. You need more contrast, but not more density. Don't overexpose, or your negatives (with the extra development) will be bulletproof. A pt/pd normal EI for me is EI 500 for HP-5+, and EI 125 for FP-4+. The extra development allows for a greater film speed than with silver printing.

[Mark_3632]

Thanks. I am aware of the density needs.

[Mark_3632]

Oops not used to that last line chop off yet. The above message should have ended with does the scene need to be contrastier? I asume notbecause of the numerous interior shots done with Pt/Pd, but I want to make sure.

I've read BTZS several times and understand the contents as well as The Negative. I have also read Arentz's book numerous times and it is now time to put it into practice once I figure out this question. Like I said I am sure there is a simple answer it is just escaping me.

[clay harmon]

Oh, you want the SIMPLE answer! No the scenes do not have to be more contrasty. You just need to process the negative appropriately for the print process relative to the scene. That said, us pt/pd guys will take pictures in contrast situations that will make silver gelatin guys run and hide, because we get a free lunch from the extra two stops of negative density range that the process requires. So, if you have an SBR of 14 and print in palladium, you can process the negative the same as a silver guy would do for an SBR of 12 or thereabouts.

[Mark_3632]

Clay

Thank you so much. Now I need the lens and I am on my way.

[sanking]

I agree with Clay that what is need for a pt/pd negative is not more overall density but a negative where the density range is higher.

The only exception to this I can think of is with films such as TRI-X, that have a very long toe but not much of a shoulder. With this kind of film it could make sense to overexpose by about 1/2 stop to kick the usable part of the curve into the straight line section of the curve. This would give you better separation in the shadows without reducing highlight separation.

[Brian Ellis]

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.

[Chad Jarvis]

The article to which Brian alludes is included in The New Platinum Print by Sullivan and Weese.

[clay harmon]

>>>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.

[james mickelson]

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.

[clay harmon]

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.