Digital contrast masks for colour printing...? Yeah!

halfaman · Aug 4, 2018

I have tried to do contrast mask for RA-4 digitally, scanning the negative and printing it with an inket printer in a transparency film (Pictorico Premium OHP). The test was done with a 6x7 negative and I blurred the image and reduced the contrast quite a lot in PS, the print was done with only black ink and following Pictorico adjustments. The outcome was like this:

Today I have done enlargements to 17x24 and 30x40 cm and the results are... PERFECT!! Just what I need!! Beautiful prints with no dodge or burns at all, compared to previous situation where I need a heavy and not easy to do dodge on the dark areas to have good detail (half the base exposure). Base exposure was affected by a 1/2 stop due to the contrast mask and it introduced a very light blue cast easy to correct. Aligment of the contrast mask and negative was done manually in a pretty straight foward way, easier than I expected.

A huge step foward to take my photographs where I want to....

slackercrurster · Aug 4, 2018

Interesting work...good for you!

tezzasmall · Aug 5, 2018

It would be interesting to see comparison prints, if possible.

Terry S

pentaxuser · Aug 5, 2018

tezzasmall said:
It would be interesting to see comparison prints, if possible.

Terry S

My thoughts exactly, Terry but you've beaten me to it

pentaxuser

halfaman · Aug 5, 2018

Ok, here they go. I tried to do it the most faithfully possible to how the prints actually look like.

On the left side: No contrast mask. 10 seconds at f/16. Dodge of 5 seconds on the right side of the river and also in the shed below the house, dodge of 2 seconds on the mountain.

On right side: Contrast mask. 9.5 seconds at f/13, no dodge or burn at all. Direct print.

I don't have any direct print without contrast mask and no dodge (I discard them), but it looks something like this:

pentaxuser · Aug 5, 2018

Thanks for the before and after and the attempt to reproduce the original if there had been no dodge at all. IMO all of the "prints" are OK i.e. can stand on their own merits and each has some pluses and minuses. What stands out to my eye and becomes my focal point is the house and this is better in the original print and dodged print. It has lost a little in the masked version( has less impact due to lower contrast). Somehow slightly softer in looks but other areas have gained detail which is harder to see in the original.

If this print were to be reproduced several times then the time to make the mask might be offset against the time taken to dodge each print and of course it avoids referring to the "map" of dodging each time. The mask certainly wins in terms of ease of use and reproducibility

There may be a way of masking that makes the house standout as much as in the original but still increases detail in other areas and if so I'd be interested in hearing from others who have done this

Overall you have done well and I can imagine negatives where masking might well bring about much bigger benefits than in this negative. You have found a "tool" that is worth further exploration.

Well done

pentaxuser

halfaman · Aug 5, 2018

pentaxuser said:
What stands out to my eye and becomes my focal point is the house and this is better in the original print and dodged print. It has lost a little in the masked version( has less impact due to lower contrast). Somehow slightly softer in looks but other areas have gained detail which is harder to see in the original.

I don't agree with your view, but this is a matter of personal taste where nothing is right or wrong. In my case the masked print is much more closer to what I want.

It is undeniable that effect of the contrast mask is very smooth and natural, very hard or even impossible to replicate with dodge and burn techniques. Take into account that not only the dark areas are recovered also the sky and the rock in the lower center have more texture that the "original".

pentaxuser said:
There may be a way of masking that makes the house standout as much as in the original but still increases detail in other areas

Of course there is and it is very easy to do in PS. You can apply an extra contrast decrease just on the house or take it to the extreme leaving it in blank so original contrast will be maintained (this is not so easy, a gradient is needed). It is possible also to do a very quick dodge on the house during printing.

pentaxuser · Aug 5, 2018

Thanks for your reply. As you say each person has a different view and if the mask has made the print look as you want it to be that is all that counts.

pentaxuser

DREW WILEY · Aug 6, 2018

Congratulations on your success. But that particular technique has been around quite awhile. I still feel that doing it the old-fashioned way using real film and a
punch and register system is far more precise in a number of ways. But if this is how you like to do things, great! Incidentally, masks are capable of efficiently doing a lot more things in color printing than just automated dodging and burning.

halfaman · Aug 6, 2018

Reading about "old-fashion" contrast masks is how I thought about doing them digitally. With film it has a number of difficult points for me, starting with the fact that most of my negatives up to date doesn't allow any kind of punch register without sacrificingng part of the image (take a look to one of them in the first picture). But this way is easy and fast to me, and I saw with this trial that there is no need to be super precise aligning negative and mask due to the blurr of the latter. The only doubt I had was the effectiveness and it is effective indeed.

DREW WILEY said:
Incidentally, masks are capable of efficiently doing a lot more things in color printing than just automated dodging and burning.

Humm... Please tell me more!

Lachlan Young · Aug 6, 2018

halfaman said:
Please tell me more!

Colour correction/ alterations to quite significant extents & saturation adjustments too. Look up how it was done for dye transfer & colour separation printing.

Mr Bill · Aug 6, 2018

halfaman said:
Humm... Please tell me more!

Have a look at Ctein's book, "Post Exposure..." presumably still available for free d/l from his website. From roughly page 100 or so.

Astronomer David Malin used USM extensively in astronomical photos to bring huge brightness ranges on a useful range. There used to be a lot of information on the internet, but I think that most of it is now gone. But probably a lot of before and after images of galaxies, etc., are still up.

As a note, you don't generally have to punch your actual negative; you can tape a strip of film to it, and put the registration punches in that.

halfaman · Aug 7, 2018

I have Post Exposure, it has been my main source for contrast masks and very helpful to build and arsenal of other techniques for color printing. I have to admit though that I really don't understand very well the contrast increasing masks, it seems that they only decrease texture of highlights but do nothing apparent for me to increase shadows density in the print.

Now I am gathering pieces of orange masks of different color films for flashing (has to be done with a piece of it, or compensate it in the filter pack which I think is harder to do accurately).

pentaxuser · Aug 7, 2018

What halfaman has been able to do is produce a slightly fuzzy B&W scan which has had the desired effect and align it by hand to get the desired effect. I had always thought that the mask had to be sharp or certainly sharper than his mask is and alignment by hand was courting trouble but based on his prints none of this seems to be the case.

Was he lucky or do we need to question whether we make masking more difficult than it needs be?

pentaxuser

MattKing · Aug 7, 2018

pentaxuser said:
What halfaman has been able to do is produce a slightly fuzzy B&W scan which has had the desired effect and align it by hand to get the desired effect. I had always thought that the mask had to be sharp or certainly sharper than his mask is and alignment by hand was courting trouble but based on his prints none of this seems to be the case.

Was he lucky or do we need to question whether we make masking more difficult than it needs be?

pentaxuser

It is, by definition, an unsharp mask.
Exactly what one needs.
Question to the OP - how is the mask oriented to the negative? In particular, do you have the ink in contact with the negative's emulsion, ink separated from the negative's emulsion by the film substrate or ink separated from the negative's emulsion by both the film substrate and the mask's substrate?

DREW WILEY · Aug 7, 2018

You can register by eye over a light box if you are just trying to learn the ropes, and if your masks are quite unsharp. 35mm film can be registered by aligning the sprocket holes. Serious or repetitive work requires a punch and matching pin glass. Film punches make tiny holes close to the edge of the film. Small film sizes can be taped to a strip of sheet film for this task, so avoid holes entirely. "Estar"-based sheet film should always be used for its flatness and dimensional stability.
Both FP4 and TMX100 are excellent masking films; and highly dilute HC-110 is a good developer (just the basics at the moment, no details). A 5-mil piece of mylar, frosted on both sides, is generally used in between, with the two emulsions facing each other. The degree of diffusion can be adjusted by the softness of the sheet - all the way from tight enhancement of edge effect (something PS mimicked) to broad diffusion. Andf just like in shooting nature, you can used black and white contrast filters to alter how hues are either emphasized or de-emphasized in relation to lighter vs darker. This is easier to learn with slides than color neg film. Often with color negs you need an extra step - a crisp contact-printed b&w interpositive to generate an unsharp CONTRAST INCREASE MASK. Otherwise, if you do it one-step, you get a CONTRAST REDUCTION MASK. That's enough for now. But already it's a way way bigger tool kit than most darkroom color printers have.

halfaman · Aug 8, 2018

MattKing said:
It is, by definition, an unsharp mask.
Question to the OP - how is the mask oriented to the negative? In particular, do you have the ink in contact with the negative's emulsion, ink separated from the negative's emulsion by the film substrate or ink separated from the negative's emulsion by both the film substrate and the mask's substrate?

No ink contact, separated from the emulsion by the mask substrate. Emulsion and mask facing up.

MattKing · Aug 8, 2018

halfaman said:
No ink contact, separated from the emulsion by the mask substrate. Emulsion and mask facing up.

So you are exposing with the negative's emulsion facing toward the light source, not the paper?
Do you not end up with a mirrored image in the print?

DREW WILEY · Aug 8, 2018

One more advantage of traditional punch and film technique. There are numerous masking applications where it is necessary to flip one film or another, like the double-neg interpositive to interneg mask trick I described. A linear punch makes this quite precise and intuitive. Multiple masks? No problem. All can be easily registered. You see, "unsharp" is a relative term. Ideally, you want to be able to precisely control the degree of that too. For some types of masks, like lith highlight masks, you want a very tight correspondence with tiny little bits of sparkle and specular reflection in the original, so no diffuse unsharpness at all. Aligning that kind of thing to your original can be tedious nerve-wracking without a punch system.

halfaman · Aug 8, 2018

MattKing said:
So you are exposing with the negative's emulsion facing toward the light source, not the paper?
Do you not end up with a mirrored image in the print?

I said it wrong! Emulsion facing down, mask facing up. Sorry.

DREW WILEY said:
One more advantage of traditional punch and film technique. There are numerous masking applications where it is necessary to flip one film or another, like the double-neg interpositive to interneg mask trick I described. A linear punch makes this quite precise and intuitive. Multiple masks? No problem. All can be easily registered. You see, "unsharp" is a relative term. Ideally, you want to be able to precisely control the degree of that too. For some types of masks, like lith highlight masks, you want a very tight correspondence with tiny little bits of sparkle and specular reflection in the original, so no diffuse unsharpness at all. Aligning that kind of thing to your original can be tedious nerve-wracking without a punch system.

Ok, you convinced me, I will explore the registered system also but also with digital masks. Contrast incresing mask is definitevely something I want to explore, double development technique is too harsh sometimes, and I would need a precise aligment with it.

I have in mind a general idea but it needs to be specified for my Durst L1200... Let's see where it drives me.

Andrew O'Neill · Aug 8, 2018

Whenever I print a negative, I almost always employ an unsharp mask. Usually made with some copy film that I have, or even xray film. I have never used a digital unsharp mask, but I have made dodge/burn masks digitally. I use them sometimes for alt printing in-camera negatives. They work great.

DREW WILEY · Aug 8, 2018

The bigger the film is, the easier masking becomes. But alas, the more expensive the film becomes. I don't shoot anything larger than 8x10, but that's ornery enough in price. Its hard to find matched sets of film punches and masking contact frames with the necessary pins; but they do turn up from time to time. Or someone with machine shop skills could make their own. I still have my original custom-order Condit equipment. Masking was routine for Cibachrome printing. But I do it about half
the time with color negs, and once in awhile for black and white images. I find that kind of darkroom work fun. There are just so many creative ways to do it. Simple masks can even be made using pencil smudge or India ink right on the frosted mylar. The hardest part is simply getting every speck of dust off glass and film repetitively. But doing it manually isn't any worse in my opinion than having to do the clean-up afterwards in PS. Meticulous cleanliness is invaluable either way.
Pan film is necessary for color image masking. But even in b&w printing I find it much easier to control than ortho-litho film.
No need to have a registered neg carrier for masking work. The final printing mask is simply taped in register to the original
shot for printing, then into an ordinary glass carrier (glass both sides, preferably both anti-newton).

halfaman · Aug 9, 2018

Durst had a pinch registration system, MIVALO registration punch and MIVADAP pinch sets for film holders. Both are very rare to see nowadays but appear from time to time in the second hand market. Lynn Radeka has a propietary system that unfourtenately is not compatible with my enlarger. I will try also to tape them as suggest by Drew.

Thanks for all your explanations, Drew!

DREW WILEY · Aug 9, 2018

Just be certain the tape itself is very thin dimensionally-stable mylar, and not ordinary acetate. Once registered, I press the two sheet of film flat together with a simple smooth Bondo applicator while gently applying the tape edge to edge before pressing it firmly down. Durst punches are almost impossible to find, and
require large strips of attached film with big holes. I do have registered carriers for both my 5x7 and 8x10 Durst enlargers, matched to my Condit system; but this is for sake of serial color separation work, like in dye transfer printing, or hypothetically, serial tricolor enlargement onto color RA4 paper. No need for that kind of fancy carrier at all in ordinary color printing.

MEB · Aug 29, 2018

I am working with digital negatives but only for B&W printing so far. I have also used the RA-4 process to print from color negatives. Allow me the simple question - how exactly did you apply the contrast mask and what exactly is step-by-step your process to create the digital negative from a color negative? I don't fully follow you in your first post to see how you made the digital negative with (or without?) an orange background?

Digital contrast masks for colour printing...? Yeah!

halfaman

slackercrurster

tezzasmall

pentaxuser

halfaman

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halfaman

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DREW WILEY

halfaman

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Mr Bill

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Digital contrast masks for colour printing...? Yeah!

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