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Stephen Thomason
2-Dec-2015, 18:10
Thanks to the many posts on this forum regarding the exposure and development of the various X-ray films, I have learned how to use the single emulsion Carestream film.

My problem is in contact printing a high contrast still life. My background is black velvet and the subject matter are flowers (yes, the petals are red/orange, the leaves are dark green, and they both are nice and dense on the otherwise clear negative, with detail).

I have established minimum exposure/maximum black (Ilford MGRC IV) using a dichroic head at full (170) magenta filtration. The black background prints black. The subject prints dark, dark grey, rather than a much higher zone as it would on panchromatic film.

I can get a higher zone for the subject by printing with Yellow filtration instead, but then my background (clear to just a tiny bit of exposure showing on the negative) prints grey.

I suspect the blue base tint of the negative is the primary reason I am having difficulty, since I believe cyan filtration acts as an ND filter with ortho films. I am using Rodinal 1:100, and it makes a really nice looking negative. Should I consider Pyrocat-HD? Would the pyro stain the subject area enough to compensate for the blue base of the negative?

Am I missing something, or am I asking this film to do something it can not? I think the film is going to work great for landscapes and portraits, but maybe not for the "almost black on white" effect that I am looking for.

Any help would be greatly appreciated.

Fr. Mark
2-Dec-2015, 19:44
I love that film, but I mainly use it for cyanotypes. I can get full tonal range with those. I use Pyrocat HD but I think cyanotypes would work well with enough density with Rodinal. I've also enlarged small bits of the film developed in home brewed Rodinal without filtration and gotten pretty much full tonal range but it was gifted silver gelatin printing paper in foil wrappers of unknown kind.

Hopefully, someone who knows more will chime in.

koraks
2-Dec-2015, 22:43
If you're already at full magenta, ie the hardest grade, then that suggests your negative is underexposed and/or underdeveloped. Have you tried printing this negative with an alternative process? When I develop xray negs for cyanotype, van dyke and carbon, I generally end up with negatives that print at 00 filtration (full yellow). I myself have wondered if the blue base boosts the contrast, but having done no sensititometry, I can't tell for sure.
Btw, when I expose generic xray film, I rate it at 50 to 100 and develop for 5 to 7 minutes in rodinal 1+100 (agitation every minute or even continuously) or 7 to 10 minutes with moersch finol (a staining developer) 1+1+150.

Ps: I often end up with negatives that are even too contrasty for van dyke and will print only well with new cyanotype with some extra citric acid added to the sensitizer to bring down the contrast of the print.

Stephen Thomason
3-Dec-2015, 06:58
koraks: I am developing for 4 minutes at Rodinal 1+100 with continuous rotation. I rate the Carestream at 25, using electronic flash (White Lightnings at full power close up), and get a nice dense negative. I've shot the same scene at 12, and the image is definitely blocking up, but doesn't look visually much denser, and the background starts to show some texture.

I've seen mention of Rodinal 1+200 for six minutes.

I'll try Rodinal 1+100 for 7 minutes as you do, and Pyrocat-HD 1+1+150 for 10 minutes and report back.

I will also try full yellow (170 on my enlarger) and see what effect that has. My exposure factor charts don't go beyond 90Y - any idea what I need to use as an exposure factor going from 90 to 170 on an Omega Dichro?

When you say you end up with negatives that print at 00 filtration, do you mean printing on standard printing paper or do you use your enlarger for printing the cyanotypes? I've yet to try cyanotypes, but they are on my list.

Fr. Mark: What Pyrocat-HD dilution do you use?

koraks
3-Dec-2015, 09:12
Is it possible your negatives are overall dense but low in contrast? E.g. fog from a not so safe safelight? I've had a lot of problems with that with green sensitive film as a regular safelight (e.g. Kodak oc) isn't suitable at all for green sensitive film and even several red led lights are known to cause fog with this film. I guess it's hard to tell for sure without having seen the negatives in person.

I print cyanotypes with a uv light source, not with an enlarger (that would take hours or even days of exposure). The negatives developed in rodinal print about right at grade 0 or 00 filtration with regular multigrade silver gelatin paper.

ic-racer
3-Dec-2015, 12:51
Increase negative development by 20% next time. Also, make sure you min-exposure-max-black is not too dark. Slightly off total black is more the norm when excelent prints by the masters have been evaluated.

Stephen Thomason
3-Dec-2015, 12:57
koraks: No, they aren't fogged, the base is nice and clear, although blue! I did a safelight test with my Kodak red filter, and no fogging was apparent up to 7 minutes. However, I really don't see any advantage in using a red safelight since I can't really see anything anyway with it, so I work in the dark when working with any kind of film.

I'll check your prior posts for info on cyanotypes. That is on my list to try.

Fr. Mark
3-Dec-2015, 19:05
I rate Ektascan at 100 under daylight balanced lights or mid-day and add stops for less blue light.
PyrocatHD 2:2:100 I'd have to find my notes which are in a pile of boxes in the future darkroom after a recent move. I'm thinking when it was still 76 or so in darkroom the time was 5:30 with longer times when colder per the Ilford chart for temp corrections. I use new cyanotype my favorite paper so far is Arches Hotpress water color paper that's been treated in 5% HCl to remove the chalk. But for tests I use some 20% cotton typing paper I found at a thrift store. It will be a while before I use up 1000 sheets of that with 5x7's. It's a little fragile when wet but is ok. I tend to "develop" the prints in 1% HCl to maximize contrast. I can get dark navy blues all the way down to paper base highlights. UV is a home built 6 t8 fluorescent bulbs from top bulb dot com though sometimes the local restaurant supply store carries them for bug zappers. I use a darkroom timer. With Ektascan per above exposure times run 45 sec to 10 minutes. 45 sec is probably under exposed/developed and or digital negatives that may not be dense enough 10 min too dense. Sweet spot may be 2-4-6 minutes. Once I get darkroom back I want to try carbon prints and maybe some day full color carbon...I also note Ektascan's antihalation layer is a wonderful thing not common on XRay films and the film is available 14x17 inches. Tempting...

koraks
4-Dec-2015, 02:01
Are you using new cyanotype or regular? It makes a huge difference in terms of contrast/tonal scale. The regular chemistry is a lot less fussy when it comes to paper. It prints well on just about any art paper I've tried; only plain copier paper yields blotchy results. Not so with the new formula by Dr. Ware; I've only found one (affordable) paper so far that works well with it. I don't pretreat it with acid, but add one drop of 40% citric acid per ml of sensitizer and develop in a first bath of water with a tiny amount of citric acid added to it (concentration of around 0.3% or even less). I found that using citric acid yields a sloghtly warmer hue than using acetic acid, which I used before. The acetic acid yields a more greenish hue (but with clear highlights, so it doesn't seem like it's an issue with undissolved iron salts, but that's conjecture on my part).

I'm puzzled by the story of Stephen; it seems your negatives should print fine on silver gelatin and cyanotype. I'm not sure where the contrast issues come from; perhaps trying cyanotype would give some more insight. Try the regular formula first, as it's cheap and easy to get hold of. If that still prints with too low contrast, then there's a problem with the negatives. If they print well with the regular formula, the negatives are still low in contrast but should print well on grade 3 or 4 paper.

Fr. Mark
4-Dec-2015, 20:24
New cyanotype for me.
It is picky about paper quality.
Ordinary copier paper varies quite a bit but I never found any with enough wet strength or freedom from blotchy-ness, not that I made an extensive survey.
If you follow the sales in the art supplies world, Arches Hotpress in 22x30 sheets a couple years ago was maybe $4 a sheet, iirc. It also comes in rolls, I think. Dr. Ware has some paper recommendations but I think those reflect the UK marketplace.
In the US: cheap joes, jerrys art o Rama, Dick blick. Utrecht all run sales from time to time.

Fr. Mark
4-Dec-2015, 20:31
The chemicals for the new cyanotype aren't that expensive, it has longer tonal range, it's a single solution that keeps 6-12 months easily, more if you put in a smidgen of dichromate. The 100ml recipe will make probably 40-50 8x10's.

http://www.mikeware.co.uk/downloads/Cyanomicon.pdf Big PDF v complete.

http://www.mikeware.co.uk/mikeware/New_Cyanotype_Process.html Less detailed, v useful

Dr. Ware has in the past responded to emailed questions. He's done a lot of great service for the photo community.

koraks
5-Dec-2015, 01:45
Yeah, I found that a home mixed new cyanotype sensitizer kept well for over half a year even without dichromate. If you mix up a small batch at a time (I mix something like 50ml or 100ml), you don't have to worry about it going bad. Iregret having added a small amount of dichromate to my latest batch as it has a longer tonal scale without it, which suits my more contrasty negatives. I'd recommend adding any contrast agents only to the sensitizer just prior to coating for that reason.

It took me quite a while to figure out how to consistently get good prints with the new formula, while the classic formula is much easier due to its forgiving nature in terms of paper. On the other hand, the new formula can match just about any negative by using contrast agents; the regular formula is much more limited and requires careful contrast control in the negative (digital negatives are ideal for classic blueprints). The regular formula is also easier to coat evenly; I find that the new formula is more prone to streaking.

I would recommend starting out with the classic formula to get a hang of the basics of alt process printing and then stepping up to the new formula for more control.

Stephen Thomason
5-Dec-2015, 17:36
Fr. Mark and koraks: I just finished developing two identical shots, one in Rodinal 1+100 @ 70 degrees F for 8 minutes, and the other in Pyrocat-HD 1+1+150 at 70 degrees F for 10 minutes.

WOW - what a difference in negative densities while still giving a Zone 0 density to the black background. They look GREAT. I think they will print substantially better than the others. The Pyrocat negative stained very well - it doesn't look as dense to the naked eye as the Rodinal one, but I am still learning the comparative effects of the two developers.

I'll update the thread when I get a chance to print these negatives. I think I am really going to like this film.

koraks
6-Dec-2015, 01:41
The stain will be particularly noticeable with alternative processes as it blocks the actinic light really well. In my negatives I guesstimate that it adds at least a stop more contrast.

Fr. Mark
6-Dec-2015, 20:50
It is possible to over do it with Pyrocat and get excessive exposure times for new cyanotype. Glad to help. I think it's a really great film at a reasonable price. I hope we have it a long time.

koraks
7-Dec-2015, 01:20
My densest negatives so far require exposure of about 3 to 4 minutes at short distance with a face tanning unit, or occasionally up to 6. But they require exposures of up to half an hour or even more for carbon transfer...

Luis-F-S
29-Feb-2016, 14:57
Not to highjack this thread, but I'm trying to expose and develop EB/RA in HC-110. I exposed at 80 EI, and developed in tanks with 2 oz HC-110 to 126 oz of water for 6 minutes at 68 deg. My highlights are very dense, 1.86 density and Zone 1 is non existant resulting with the image being very contrasty. What other developer combo and EI should I use to try and tame the contrast? I'm afraid with the HC-110 I would need to decrease the developing time too much. I would like to produce negatives for silver gelatin printing. Thanks, L