Increasing contrast in Kallitypes -- dichromate or photoshop?

[Rolleiflexible]

I have run through the process of linearizing curves for printing digital negatives as Kallitypes, which I am toning in platinum. I am getting decent images, but they look a bit flat to my eye. This makes me realize that while I might have the curves right, my digital files may be too flat for printing -- I have edited them to display correctly on a monitor, not for printing.

Now it occurs to me that I could increase contrast two ways. I could add a drop of potassium dichromate to the sensitizer, which I gather would increase contrast. Or I could increase contrast in Photoshop before printing the negative.

Any thoughts about the options? I am thinking I am better off increasing contrast in the negative because that will play nicely with my current print curves and exposure times. If I add dichromate, then shouldn't I run new tests to establish new exposure times, and to create new print curves? Are there reasons to add dichromate to the sensitizer, apart from kicking up contrast?

Many thanks in advance for your thoughts.

Sanders McNew
www.flickr.com/sandersnyc
www.instagram.com/sandersnyc

 

[revdoc]

If you can get enough density in your digital negs, you can get all the contrast the process can deliver. So that's where I would start... do a maximum black test, and maybe repeat linearisation if required.

But before that, what do you mean by "they look a bit flat"? Are the blacks too weak? The highlights too grey? Some of these things can be adjusted by double coating and different developers. Toning might also increase dmax.

It's also worth noting that prints always look different to what you see on a monitor. I have "preview" curves that I use to check how an image will look as a print. The results are darker and flatter, but that's what the prints are.

 

[Andrew O'Neill]

I would tweak the negative.

 

[Rolleiflexible]

If you can get enough density in your digital negs, you can get all the contrast the process can deliver. So that's where I would start... do a maximum black test, and maybe repeat linearisation if required.

But before that, what do you mean by "they look a bit flat"? Are the blacks too weak? The highlights too grey? Some of these things can be adjusted by double coating and different developers. Toning might also increase dmax.

It's also worth noting that prints always look different to what you see on a monitor. I have "preview" curves that I use to check how an image will look as a print. The results are darker and flatter, but that's what the prints are.

Using a sensitizer of ferric oxalate and silver nitrate, I have established maximum blacks, and blocking values, and linearized the curve for printing negatives using QuadToneRIP. And I do double-coat the paper, and am toning with platinum. Today, I am going to reprint the negatives with darker midtones, to see if that results in a better distribution of tone values in the prints.

Adjusting the negative is an easy fix. HOWEVER, all it can accomplish is redistribute the tones within the range provided by the chemistry. QUERY: Will the addition of a dichromate (potassium or ammonium) to the sensitized actually expand the tonal range of the print? If so, how so? Deeper blacks?

 

[busrider]

Contrast curves are a beautiful thing.

I would tweak the negative.

Indeed

 

[nmp]

QUERY: Will the addition of a dichromate (potassium or ammonium) to the sensitized actually expand the tonal range of the print? If so, how so? Deeper blacks?

The way I understand, dichromate actually would shorten the scale not expand it. If your Dmin is already at paper-white, addition of dichromate is going to blow out your highlights and then you will need to increase the exposure and/or tweak the correction curve to bring them back in. That would affect the Dmax too, up or down? Will have to experiment to see. Mike Ware's Cyanomicon has a comparison (check Figs. 7.1 and 7.2) that shows that for New cyanotype at least, the Dmax seems to come down with dichromate, per my reading.

:Niranjan.

 

[Rolleiflexible]

The way I understand, dichromate actually would shorten the scale not expand it. If your Dmin is already at paper-white, addition of dichromate is going to blow out your highlights and then you will need to increase the exposure and/or tweak the correction curve to bring them back in. That would affect the Dmax too, up or down? Will have to experiment to see. Mike Ware's Cyanomicon has a comparison (check Figs. 7.1 and 7.2) that shows that for New cyanotype at least, the Dmax seems to come down with dichromate, per my reading.

:Niranjan.

This is really helpful. Thank you!

 

[Andrew O'Neill]

Does your exposure time produce a convincing black? Did you conduct a min time max black test through the film? How do the highlights look? I use QTR, which allows me to control how much ink is being laid down on the film. Are you able to back off on how much ink you are using?

 

[Rolleiflexible]

Does your exposure time produce a convincing black? Did you conduct a min time max black test through the film? How do the highlights look? I use QTR, which allows me to control how much ink is being laid down on the film. Are you able to back off on how much ink you are using?

I am getting black values that are similar to what I have gotten with palladium prints. I experimented with longer exposures but got solarization, not deeper blacks. I did test for max black through a sheet of film. Highlights are not paper-white, but close. I am using Richard Boutwell's program, QuadToneProfiler, to linearize the QTR curve. I'll attach a shot of the last print, of an old photo I posted to APUG ages ago:

Hair, cut.

www.photrio.com

As you will see, the Pt/Kallitype lacks sufficient contrast between skintones and background, and also among skin tones in hands and shoulders. I think I can balance it out by darkening midtones with the gamma slider and reprinting the negative, but it does make me wonder whether I am missing something for the tones to diverge this much from the original file.

 

[Andrew O'Neill]

I am getting black values that are similar to what I have gotten with palladium prints. I experimented with longer exposures but got solarization, not deeper blacks. I did test for max black through a sheet of film. Highlights are not paper-white, but close. I am using Richard Boutwell's program, QuadToneProfiler, to linearize the QTR curve. I'll attach a shot of the last print, of an old photo I posted to APUG ages ago:

Hair, cut.

www.photrio.com

As you will see, the Pt/Kallitype lacks sufficient contrast between skintones and background, and also among skin tones in hands and shoulders. I think I can balance it out by darkening midtones with the gamma slider and reprinting the negative, but it does make me wonder whether I am missing something for the tones to diverge this much from the original file.

Is that the same paper you used for palladium prints? Which paper are you using?

 

[Rolleiflexible]

Is that the same paper you used for palladium prints? Which paper are you using?

Yes. Hahnemuhle Platinum Rag for both. EDIT: I should add that I am following Sandy King's recipe for printing Kallitypes. And I am working in a windowless space lit by LED fixtures that emit no UV radiation. (I double-checked that with a UV light meter.)

 

[nmp]

Wouldn't this change after toning? I would do the toning and see where it takes you. If you intend to tone for sure, you might want to include that in your digital negative correction curve as well because toning presumably will change somewhat the tonal relationships between shadows, midtones and highlights too.

Also, on your digital photo, if you apply a curve - which is a straight line with points (0, Dmax) and (255, Dmin), you will get the simulation of how the kallitype will look like with a perfectly linearized negative. This will give you an idea how far from the theoretical your actual print is. You will get a better idea if you use the step wedge you used to do the curve calculations. If they don't look identical, the curve is deficient somehow.

:Niranjan.

 

[Andrew O'Neill]

Yes. Hahnemuhle Platinum Rag for both. EDIT: I should add that I am following Sandy King's recipe for printing Kallitypes. And I am working in a windowless space lit by LED fixtures that emit no UV radiation. (I double-checked that with a UV light meter.)

It's the same paper that I use. I'm not familiar with Richard Boutwell's profile. I do use QTR, but only to control which ink and how much is used... I've always used Chartthrob's step wedge to calibrate curves, and prefer to attach the curve to the positive image (then inverting), before it's printed with the profile. I had a friend once who was getting flat contrast because he was double curving by accident. It took him a heap of prints and chemicals before he realised that he was attaching the curve to the image, when the profile had the curve in it already. He removed the curve from the profile, a Bob's your uncle!
That is probably not your issue. I would start with what you suggested, and adjust your gamma slider. Is that something in the PC version of QTR? Mac version accepts numbers only...

 

[Rolleiflexible]

Wouldn't this change after toning? I would do the toning and see where it takes you. If you intend to tone for sure, you might want to include that in your digital negative correction curve as well because toning presumably will change somewhat the tonal relationships between shadows, midtones and highlights too.

Also, on your silver gelatin photo, if you apply a curve - which is a straight line with points (0, Dmax) and (255, Dmin), you will get the simulation of how the kallitype will look like with a perfectly linearized negative. This will give you an idea how far from the theoretical your actual print is. You will get a better idea if you use the step wedge you used to do the curve calculations. If they don't look identical, the curve is deficient somehow.

:Niranjan.

I toned with platinum as part of the linearization process -- after the wash but before the fix, as per Sandy King's directions. The toning does alter density but that is already factored into the process I followed here.

 

[Rolleiflexible]

I would start with what you suggested, and adjust your gamma slider. Is that something in the PC version of QTR? Mac version accepts numbers only...

No, I too am on a Mac. I am changing the image gamma in Photoshop (actually, in Affinity because I refuse to pay Adobe nosebleed prices) and then reprinting the negatives.

 

[nmp]

I toned with platinum as part of the linearization process -- after the wash but before the fix, as per Sandy King's directions. The toning does alter density but that is already factored into the process I followed here.

Oops...I thought I saw somewhere in the thread you hadn't toned yet. Never mind.

It's hard to discern on the browser photo, but it does look to me that your Dmax is kind of low based on the border. Unfortunately, solarization/bronzing is like a hard stop for Dmax. In salt prints I found that drying more thoroughly moved the "bronze point" higher giving me a slight boost on the Dmax. I don't know if there is anything like that in the kallitype repertoire.

:Niranjan.

 

[Rolleiflexible]

Niranjan, thanks for the feedback -- I appreciate your time and thoughts. BTW I looked at your Zenfolio and really liked your albumen images. Is POP still available?

 

[nmp]

Niranjan, thanks for the feedback -- I appreciate your time and thoughts. BTW I looked at your Zenfolio and really liked your albumen images. Is POP still available?

You are welcome. I like to solve (or take a stab at) these little puzzles alt processes throw at you....more than making actual prints these days, I'm afraid.

Thank you about the POPs. Those are not albumen but gelatin chloride, by the way. And no, unfortunately they stopped making those in mid-2000's. I might have bought the last pack..... Hard to come by in the secondary market now as well.

:Niranjan.

 

[Rolleiflexible]

Update: I printed a test using a negative with markedly darker midtones. The result was a marginal improvement, but not a complete fix.

I am wondering whether the issue is with my chemicals. I mixed this batch of ferric oxalate 10 days ago. It should still be good. But I am running out of culprits.

 

[Andrew Keedle]

My (simple) understanding was to control contrast in a Kallitype you add the contrast agent to the developer. Also the developer exhausts as opposed to Pt/Pd. Are you replenishing or fresh batch of developer?

 

[Andrew Keedle]

I've only used Wolfgang Moersch Kallitype with contrast booster in the developer (Sodium Citrate) and the EasyDigitalNegative process for producing curves.


Kallitype Pd toned



Kallitype Gold toned

 

[Rolleiflexible]

Update: I mixed a fresh batch of ferric oxalate and that solved the problem. I had thought it had a shelf life of several weeks so I am surprised it went off in ten days. Is this normal?

Now I have a new problem. The highlights bleached out in the clearing baths. I am attaching a snap of the print, toned in gold. I followed Sandy King’s Kallitype recipe on the Alternative Photography site, in which he specifies two five-minute clearing baths in a 3% citric acid solution.

Reading further now, I see that Sandy King’s Kallitype article on Unblinking Eye specifies a maximum of four minutes in the same solution, not ten. Of course I will retest now with a shortened clearing bath. Do you all have any thoughts as to the appropriate times and solutions for clearing the print after development?

 

[Erik L]

I have found through frustration that a step wedge won’t lie but my monitor sure will. If your printed step wedge looks perfect but it’s looks wrong on your monitor than you might adjust your monitor. I find I have to always darken the shadows on my iMac to match a good print. Just something to ponder

 

[Rolleiflexible]

Update: I shortened the two citric acid clearing bath times from five to two minutes each, and used a dilute (1:6) TF-4 fixer. And relinearized the curve (again) to reflect the changes. And reprinted the negative with the new curve, darkening gamma a wee bit.

It worked!

Lessons learned:

Use ferric oxalate in solution within a few days of mixing it.

Use an alkaline fixer.

Modest changes to midtone balance can improve the printed image, even with a properly-linearized print curve.

 

[MattKing]

FWIW, Melanie's eyes work their wonders in every example you have posted!
I hope that both of you are well.