Increase RA-4 contrast with masks

[athbr]

Would this work?

- Contact expose arista ortho lith to a 35mm colour negative
- Develop as reversal for an internegative
- Use internegative as a contact increasing mask

Or are there any other masking processes used in RA-4 that people would recommend?

 

[koraks]

It will work in part, but not entirely. The problem is the ortho film, which will result in changes in contrast that are partly dependent on the colors in the image. I'd use a panchromatic film instead.

 

[athbr]

Oh yeah I forgot about that!

Have you ever tried masking with pancro?

 

[peoplemerge]

That's really interesting. I've always heard about using interneg negatives for contrast reducing masks, but I guess processing as reversal instead of negative would mean increasing, not decreasing. I haven't tried either.

 

[Lachlan Young]

The essential instructions are in Ctein's 'Post Exposure', p.108 - the 2nd edition can be downloaded for free from his website. It's usually a two step process, and needs good register because it's a 'sharp' as opposed to an unsharp mask. You might need to experiment to find a suitable film for what you need - it would be feasible to use a panchro film for the interpositive & an ortho/ blue sensitive film for the mask itself. It can get pretty arcane with filtration being used to make colour specific masking etc. And that's before getting into developer choice etc.

 

[koraks]

No, I haven't tried it, but I'd use a film with excellent linearity. Tmax 100 would be the prime candidate.

 

[newcan1]

Much easier to increase contrast in RA4 process by adding H2O2 to the developer.

 

[athbr]

Much easier to increase contrast in RA4 process by adding H2O2 to the developer.

I have heard that but it does strike me as less consistent.

There is wastage too especially if working on multiple prints with different contrasts per session.

 

[DREW WILEY]

Your interpositive has to be on pan film. I like to use either FP4 or TMax 100 sheet film by contact. With your tiny 35mm originals, the finer grain of TMax would be preferable. The interpositive should be full range, a bit overexposed, and slightly underdeveloped. Here's the hitch - you need to calibrate the pan film to the idiosyncrasies of the color neg itself. All of this becomes easy after you've done it a few times, so don't get intimidated by my instructions.
First balance your colorhead to 5000K. Second, insert into the light path a blank shot using the same kind of color neg film as the original - this will provide the precise orange filter necessary to null out the orange mask of the original itself. If you want to get even more accuracy, add to this a no.11 Wratten or Hoya light yellow-green X0 filter to offset the reduced green sensitivity of your pan film. Develop in HC-110 (takes a bit of experimenting; but you want to arrive at a full-range mild sharp interpositive as noted above). Once you've got that, which is easy with a bit of practice, you expose your contrast reduction mask in register to it, but with an intervening sheet of 7-mil mylar frosted both sides to provide the unsharpness. I prefer to use TMax for this too; but since you're now working with just a black and white image, you could hypothetically use ortho. I just find the Arista Ortho Litho quite difficult to control well. A bigger problem is that you want your final contrast-increase mask to be very soft, with a DMax of only around .30. Masking color neg film is a lot like power steering - just a little goes a long ways; you simply don't want too much density or contrast in a color neg mask. And the trick with that is to find a film and developer combination that will provide a very long straight line at a very low contrast gamma. You can either try Ctein's Muir Softshot developer or my own tweak for TMax (for the final mask only) : HC-110 1:31 from stock (not concentrate). Stock is 1:3 from concentrate. Add 2 ml of 1% benzotriazole solution to the stock HC-110 prior to the 1:31 dilution to act as a toe-cutter. Further refinement can be done if necessary by briefly reducing mask density in Farmer's Reducer, just a minute or less. Another nice thing about TMax films is that all the residual stain of the antihalation dye washes out very quickly, and you end up with almost no edge fog, and very little density in the clear areas (only around .04). I happen to use TF-4 alkaline fixer.

 

[athbr]

Your interpositive has to be on pan film. I like to use either FP4 or TMax 100 sheet film by contact. With your tiny 35mm originals, the finer grain of TMax would be preferable. The interpositive should be full range, a bit overexposed, and slightly underdeveloped. Here's the hitch - you need to calibrate the pan film to the idiosyncrasies of the color neg itself. All of this becomes easy after you've done it a few times, so don't get intimidated by my instructions.
First balance your colorhead to 5000K. Second, insert into the light path a blank shot using the same kind of color neg film as the original - this will provide the precise orange filter necessary to null out the orange mask of the original itself. If you want to get even more accuracy, add to this a no.11 Wratten or Hoya light yellow-green X0 filter to offset the reduced green sensitivity of your pan film. Develop in HC-110 (takes a bit of experimenting; but you want to arrive at a full-range mild sharp interpositive as noted above). Once you've got that, which is easy with a bit of practice, you expose your contrast reduction mask in register to it, but with an intervening sheet of 7-mil mylar frosted both sides to provide the unsharpness. I prefer to use TMax for this too; but since you're now working with just a black and white image, you could hypothetically use ortho. I just find the Arista Ortho Litho quite difficult to control well. A bigger problem is that you want your final contrast-increase mask to be very soft, with a DMax of only around .30. Masking color neg film is a lot like power steering - just a little goes a long ways; you simply don't want too much density or contrast in a color neg mask. And the trick with that is to find a film and developer combination that will provide a very long straight line at a very low contrast gamma. You can either try Ctein's Muir Softshot developer or my own tweak for TMax (for the final mask only) : HC-110 1:31 from stock (not concentrate). Stock is 1:3 from concentrate. Add 2 ml of 1% benzotriazole solution to the stock HC-110 prior to the 1:31 dilution to act as a toe-cutter. Further refinement can be done if necessary by briefly reducing mask density in Farmer's Reducer, just a minute or less. Another nice thing about TMax films is that all the residual stain of the antihalation dye washes out very quickly, and you end up with almost no edge fog, and very little density in the clear areas (only around .04). I happen to use TF-4 alkaline fixer.

Think I might be confused with the first part.

I add a blank developed frame of print film into the enlarger and use that light to contact print my negative to the tmax 100? Is that it?

cheers.

PS: Any reason not to skip interpositive and do that one sheet as reversal?

 

[DREW WILEY]

Contact means emulsion to emulsion film in a registered contact frame, just like making a contact print. But the quality of the exposure light has first of all to be around 5000K just like a high quality viewing lightbox, which will require dialing in some magenta and cyan to your colorhead to make the light output more similar to daylight. But then you also must include a filter matching the orange color of the color neg mask, best attained simply by using an unexposed but developed portion of your 35 mm film strip, or perhaps a glass filter nearly the same hue, and placing this over your lens. An optional pale yellow-green filter can also be added to more precisely balance the green sensitivity of you pan interpositive film. Once you have mastered the basics, then specialized masks can be generated to differentially enhance or reduce the contrast of specific hues, making this a much more versatile tool than just altering the developer for a generic contrast change.

 

[athbr]

Contact means emulsion to emulsion film in a registered contact frame, just like making a contact print. But the quality of the exposure light has first of all to be around 5000K just like a high quality viewing lightbox, which will require dialing in some magenta and cyan to your colorhead to make the light output more similar to daylight. But then you also must include a filter matching the orange color of the color neg mask, best attained simply by using an unexposed but developed portion of your 35 mm film strip, or perhaps a glass filter nearly the same hue, and placing this over your lens. An optional pale yellow-green filter can also be added to more precisely balance the green sensitivity of you pan interpositive film. Once you have mastered the basics, then specialized masks can be generated to differentially enhance or reduce the contrast of specific hues, making this a much more versatile tool than just altering the developer for a generic contrast change.

Drew any books or resources to recommend for this line of printing work?

Other than Ctein's great one suggested by Lachlan.

Thanks

 

[DREW WILEY]

I don't know if Ctein ever actually did it with color negs and RA4 papers. From what he told me in person, I don't think so. I think he was writing theoretically. He mainly printed his color negs at that time via the pan matrix version of dye transfer, where the contrast is controlled by the pH of the dyes, but often with supplementary masks too. The concept itself is basic. The later Kodak color printing guides talk about it; but all the specifics are out of date. Films have changed. Very few people ever did it. Most of us who were really into masking were doing either dye transfer or Cibachrome printing. Therefore it was easy for me to adapt my experience and equipment for RA4 printing usage. Being able to make both contrast-reduction and contrast-increase masks is actually a great benefit to printing color negs effectively. I don't need to use it all the time; but it is a very valuable skill set to have.

 

[Lachlan Young]

I don't know if Ctein ever actually did it with color negs and RA4 papers. From what he told me in person, I don't think so. I think he was writing theoretically.

I'm glad I wasn't the only one who had that sense on going back and re-reading the segment - it's a good description of the principles, but nothing more. I do have a couple of BW negs I really should get on & make contrast boost masks for - though I may just lith print them & see if that aesthetic works better for the feel I want - beauty and perfection aren't necessary for them!

 

[DREW WILEY]

Masking color film is obviously a lot more specific than masking black and white originals, for which there is quite a bit in print about, or perhaps some web tutorials too. The equipment is basically the same. And when it does to color masking, the protocols are quite different with respect to the specific medium. The older literature talks a lot about masking in relation to dye transfer printing, but that's very different from what was done for Cibachrome, which in turn in quite different than masking color neg film for chromogenic printing. Even masking for Portra versus Ektar is somewhat different. But all I can state succinctly is what I already have - masking for color neg films is like power steering - you have to be careful not to overdo it; very little has a significant effect.

 

[Adrian Bacon]

Would this work?

- Contact expose arista ortho lith to a 35mm colour negative
- Develop as reversal for an internegative
- Use internegative as a contact increasing mask

Or are there any other masking processes used in RA-4 that people would recommend?

there’s a guy on YouTube that used to own a lab here in the Bay Area that has been posting videos of how to mask c-41 and RA-4 to increase contrast. His name is Timi hall: https://www.youtube.com/channel/UC9LDvShZyuH_m7GYPUr6o6g

he covers a lot of stuff that you probably already know and can be a bit dry, but you might be able to glean some useful stuff from his videos.

 

[athbr]

there’s a guy on YouTube that used to own a lab here in the Bay Area that has been posting videos of how to mask c-41 and RA-4 to increase contrast. His name is Timi hall: https://www.youtube.com/channel/UC9LDvShZyuH_m7GYPUr6o6g

he covers a lot of stuff that you probably already know and can be a bit dry, but you might be able to glean some useful stuff from his videos.

Cheers Adrian this is immensely helpful.

 

[DREW WILEY]

The Utube video is pretty slow going, so I'll have to finish it later. But so far, it seems quite worthwhile, though from my own standpoint he does a number of things the hard way. It's hard to imagine that anyone in this day and age actually prints color with gel filters instead of a colorhead, or ever did professionally, but he does use overlapping filters in a valid instructional way. And I should point out that commercial labs, who take in a very wide range of tasks from various people using different kinds of film, often need to do things a certain way which an individual printing for himself does not. You can easily learn high-quality RA4 printing without a color densitometer. A black and white transmission densitometer is certainly helpful for masking, but not essential there either. I do recommend acquiring a calibrated little Stouffer step wedge so you can visually compare approximate densities, as well as a high quality color standard as a reference, namely, a McBeth Color Checker chart, which should be protected from light, heat, and humidity when not in use. If you do get serious about masking and need to frequently do it, then a film punch and register system would be your wisest investment.