Pt/Pd vs. Silver print

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I never tried Platinum printing (the chemistry is not available in my city), but what I saw online and read about make me guess that tonal rendition in Pt/Pd is more or less close to the lowest grades of silver based paper (#00 and #0 MG). Of course with properly developed LF negative. -- Am I absolutely wrong? Has anybody printed the same negative on both sorts of paper? If yes, what is your impression?

Thank you

-- Andrey Vorobyov (AndreyVorobyov@yahoo.com), March 05, 2002

Answers

Yes, you could say that it is similar, but not the same. The Pt/Pd printing could be compared to albumen or salt prints, that is POP processes. The difference in those processes is that the density builds up while exposing the print and blocks the light from exposing more light sensitive material. In the Pt/Pd process you don't have this effect (density build-up) since the image appears when the print is emerged in the dolutions, but you still need a contrasty negative (contrast can though be controlled by mixing different amounts of chemicals when sensitising the paper). If you try to print a normal negative on Pt/Pd paper, the results might resemble what you get when printing a soft negative on a soft paper.

-- George Papantoniou (papanton@hol.gr), March 05, 2002.

Thanks, George. I understand the difference between the Print-out and usual development processes. I meant only a final look of the print (made from a negative contrasty enough). Well, if I understood correctly, your answer is "it is similar, but not the same".

-- Andrey Vorobyov (AndreyVorobyov@yahoo.com), March 05, 2002.

I have printed platinum for over ten years. There is a very big difference between silver and pt/pd prints. The tonal gradation is finer, and pt/pd prints have a longer grey scale. For me, they are much more beautiful than silver prints. But that's my opinion. Feel free to disagree.

One normally develops a negative for pt/pd printing for a stronger density than one would for a silver print. I have printed pt/pd negatives on MG paper with either a 0 or 1/2 grade filter. They are acceptable for either use in newspaper reproduction or as a "proof" print. As silver prints, they look "OK", but I wouldn't consider them exhibition quality.

-- Joe Lipka (joelipka@earthlink.net), March 05, 2002.


There is a chart of density readings from prints of step tablets developed in both pyro and D-76, which is part of Bob Herbst's article "The Effects of Pyro Stain in Platinum Printing." The chart is intended to demonstrate the longer range obtainable with pyro over D-76 negatives, but it also clearly illustrates the different print ranges available from silver and platinum. Since each step on the 21-step Stouffer wedge is 1/2-stop, you can see that the pyro neg provides a 9-1/2-stop printable range for both platinum and silver. It also illustrates that the range of reflectance of a silver print is greater, but of course many people prefer the fine gradation obtainable from a platinum print.

In the case of the D-76 negative, the silver print was able to reproduce a 6-stop range, whereas in platinum the range was 8-1/2- stops.

-- Ed Buffaloe (edb@unblinkingeye.com), March 05, 2002.


Joe, Ed, thanks. Ed, I've read the article (by the way, it is the first time I read a sensitometric details about Pyro developed negative). But the chart you mentioned shows the behaviour of silver paper of grade #2, not #00 or #0... My point is to simulate the Pt/Pd look with _softest_ grades of silver paper

-- Andrey Vorobyov (AndreyVorobyov@yahoo.com), March 05, 2002.


Andrey--One has to choose some sort of standard for a test either way. What should be your Platinum/Palladium standard? Bob Herbst ran his tests with a 60% platinum/40% palladium mixture, which is his personal standard mixture, and used a #2 paper as the silver standard. My understanding is that contrast and tonality can be adjusted by various means in the platinum/palladium process. Perhaps Joe Lipka could address this further.

Michael Smith holds that Kodak Azo contact paper has a greater range than platinum, and Azo is only available in grades 2 and 3.

-- Ed Buffaloe (edb@unblinkingeye.com), March 05, 2002.


Well, if the transfer functions look identical, the prints will similar, right? Except that the transfer functions do not look similar. Pt/Pd has a larger straight line section. Silver prints (even with the 0 filter) often have higher midtone contrast and lower contrast in the shadows and highlights.

Part of the problem comes from the ambiguous use of the term 'long tonal scale'. Some folks use it to imply a low contrast transfer function that can accomodate a long range of subject luminances (e.g., 12 zones). However, if one means a long straight line part of the curve, then Pt/Pd has a longer tonal scale than typical silver papers because silver papers distort the toe and shoulder for added midtone contrast. MG was reputed to be particularly notorious for a long toe to accomodate roll film users. Azo is the one paper I know that does provide a long straight line portion in the appropriate developer.

Cheer, DJ.

-- N Dhananjay (dhananjay-nayakankuppam@uiowa.edu), March 05, 2002.


One of the joys of Pt/Pd printing is the (almost) absolute control over contrast. The contrast is controlled by varying the proportion of two solutions: ferric oxalate and ferric oxalate with potassium chlorate. The "color" of the Pt/Pd print is determined by the mix of Pt (cooler) and Pd (warmer). My personal preference is about 2 to 1 Pd to Pt. This gives a fairly warm image. The 60-40 ration would more than likely be a cool to neutral tone.

My designation of the "long tonal scale" was clarified above. A "longer straighter journey from black to white" describes what I see in a Pt/Pd print.

I have read much about Azo on this site. I have never used it. But, there are those that highly recommend it. Give it a try. I know you can't duplicate the look of a platinum print on silver paper.

-- Joe Lipka (joelipka@earthlink.net), March 05, 2002.


Gentlemen, thanks a lot. DJ: -- have you got any sensitometric information (tables, graphs) about curves of Pt/Pd and Azo papers?

I'm experimenting right now with MG #0-00 papers and have found that this grades (compared to higher grades) have much _constant_ contrast along the characteristic curve (more stright shape of the curve), especially the #00. I got some very nice results (portraits with "long tonal scale") that are somewhat unusual for silver based paper (at least in my experience). Exactly this fact provoked me to think that silver ##0-00 print can aproach the character of Pt/Pd print.

Your input is still welcome.

-- Andrey Vorobyov (AndreyVorobyov@yahoo.com), March 06, 2002.


I don't know which developer DJ considers appropriate for achieving extended straigt line response. Here are Kodak's curves for grades 2 and 3 Azo in Dektol:

http://www.kodak.com/global/en/professional/support/techPubs/g10/f009_ 0104ac.gif;jsessionid=4LUKCU4J0P0V1QHIO2SXWIA

http://www.kodak.com/global/en/professional/support/techPubs/g10/f009_ 0105ac.gif;jsessionid=4LUKCU4J0P0V1QHIO2SXWIA

They have long toes, more pronounced with grade 2 than 3. That is why folks find them so easy to print on without burning out highlights. It's also why some images may not "sparkle" as much as renditions of the same negatives on other papers.

-- Sal Santamaura (santamaura@earthlink.net), March 06, 2002.



Hi Andrey

I'm afraid I don't have sensitometric information of Pt/Pd. I do have a bunch of curves plotted for Azo in various developers and a few other papers. Let me know if you would like to take a look at these and I'll email the spreadsheets to you.

Hi Sal

I've seen the Kodak data sheets of Azo in Dektol - and my results parallel those. But Azo is actually a pretty flexible paper and provides considerable changes in curve shapes with different developers. In the limited range of things I've tried, I've got very good results with Amidol and with Ansco 130.

Cheers, DJ

-- N Dhananjay (dhananjay-nayakankuppam@uiowa.edu), March 06, 2002.


DJ kindly sent his curves for Azo. I've never seen such varied results from a single paper type in different developers. His data strongly suggest one should try Amidol as a way to circumvent Azo's long toe in Dektol, and I'll do just that as soon as time permits. Thanks, DJ!

-- Sal Santamaura (santamaura@earthlink.net), March 12, 2002.

DJ: curves received, thanks!

Sal: if you circumvent Azo's long toe, what the remaining virtue of Azo you want to enjoy? (This question implicitly assumes that the long toe is the only virtue of Azo -- it follows from your answer above.)

-- Andrey Vorobyov (AndreyVorobyov@yahoo.com), March 13, 2002.


Andrey, I didn't mean to imply that a long toe is Azo's only virtue. On the contrary, I have always found Azo's long toe (particularly grade 2) problematic. It forces development of negatives to a very high gamma in pursuit of really white print whites, resulting in excessive midrange contrast.

The Azo curves DJ supplied are interesting because those for Ansco 130 and - - especially - - Amidol are almost all straight line, i.e. practically no toe or shoulder. Making large format negatives that can be individually developed to match the density range of Azo in one of these developers affords an opportunity to control tonal scale without distorting it. They may exist, but I don't know of any enlarging papers which behave that way.

Other Azo characteristics I enjoy are a surface with just the right amount of gloss to look good but not result in newtons rings and a sensitivity compatible with regular light bulbs, thus obviating the need for an enlarger. This latter virtue also leads to excellent long term storage performance.

-- Sal Santamaura (santamaura@earthlink.net), March 13, 2002.


For those who would like to see the curves DJ plotted (and some photographs on Azo), I have added them to my Azo page.

-- Ed Buffaloe (edb@unblinkingeye.com), March 13, 2002.


Sal, I apologize for misspell, of course from your answer followed, that the long toe hurts, therefore it is not a virtue. Your answer clarified this. Thank you.

More input is welcome.

-- Andrey Vorobyov (AndreyVorobyov@yahoo.com), March 14, 2002.


In general, striving for as much of a straight line response is probably a good idea. A straight line print response best preserves the information and gradients in the negative (when properly scaled). Also, I suspect prints often look better (i.e., no abrupt increases or decreases in gradation in some area of the scale) although this is clearly a personal, aesthetic issue. Finally, it is easy enough to distort the curve. Techniques such as preflashing, pre-development bleaching, water bath etc distort either the toe or the shoulder. Getting a straight line response, though seems to need help from emulsion characteristics. Variable contrast papers can sometimes be particularly troublesome. The two emulsions obviously complicates issues (I've seen some D-log E curves that actually had a flat middle portion - due to mismatches in the speeds of the two layers) - Ctein talks about this ("Post Exposure") and has a couple of prints to demonstrate the problems. Cheers, DJ.

-- N Dhananjay (dhananjay-nayakankuppam@uiowa.edu), March 14, 2002.

N Dhananjay wrote: "I've seen some D-log E curves that actually had a flat middle portion".

DJ, what kind of paper/developer it was? -- It is possible to derive a great benefit from such a behavior: when a negative match the paper grade, the negative toe gets combined with paper toe (and shoulder with shoulder also). It lowers the contrast in shadows and in highlights of the final print. If we only had such a paper that at the start and at the end of the curve had higher contrast than in middle tones, then we could get rid of that lowering. David Kachel had in Internet an article (cannot find it now) devoted to this topic; his goal was to get the curve shape you speak about; but his technique was complex enough (bleach, then redevelop in a special way).

To turn our disadvantage to our own advantage -- I think it is a good way to work (to live, to fight..), isn't it? :)

-- Andrey Vorobyov (AndreyVorobyov@yahoo.com), March 15, 2002.


Hi Andrey

I don't remember the exact combination now, I'm afraid. I want to say Forte's polycontrast paper, but I honestly do not remember. The problem might have been with just that specific batch as well. Multicontrast papers have two emulsions (mor more) of different speeds (and spectral sensitivities). When the speeds are appropriately matched, one gets a propser H-D curve. However, if there is some problem with the speeds (for e.g., the shoulder of the low contrast green emulsion does not link up properly with the toe of the high contrast blue emulsion), you can get a flat midtone section.

David Kachel had an artcile (I think it was called "Cursing the Curve - but can't remember it for sure) where he talks about what you suggest (i.e., trying to manipulate a paper curve so that the high contrats middle section of the negative is combined with a flat middle portion of the paper curve and the low contrast toe and shoulder of the film are combined with a higher contrast toe and shoulder of the paper). He discussed using a combination of developers and monobath developers to try and arrive at such a curve. I could try to dig up the details, if you would like.

Cheers, DJ.

-- N Dhananjay (dhananjay-nayakankuppam@uiowa.edu), March 18, 2002.


Ok, DJ, it is very possible that is was a property of the specific batch.

I have printed all the articles of D.Kachel when the articles were available online, so don't dig up.

Thank you very much for your answers!

-- Andrey Vorobyov (AndreyVorobyov@yahoo.com), March 21, 2002.


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