Reversal RA-4 experiment thread.
Reversal RA-4 processing is discussed a little in many threads, but there's quite little definite experimental information available.
I've done my own little research for two years, every now and then when I have something else to do and want to escape from it . I've spent a few nights experimenting. I've thought of making some kind of Reversal RA-4 manual after I've enough results, but as I'm not sure if that day will ever come, I'll start now by giving all these little results I have now, and ask you also to publish your results!
Reversal RA-4 is much fun! I genuinely recommend experimenting a little. You may be surprised how easy it is to get nice positive images, though not flawless.
So, here I go.
Reversal RA-4 processing involves a first developer, basically a BW developer, then wash, light reversal (with room lighting), normal RA-4 color dev and blix and wash.
This will produce usable positive prints from slides, having some inevitable problems, because the RA-4 papers are not designed for this kind of use but for printing negatives, having lower contrast index.
What we want, is a tone scale of about 3.0...3.3 D, or 10 to 11 stops. This is about the tone scale of slides, and has to include the toe and shoulder of the paper to get proper white and black. Some compression of toe and shoulder is inevitable and present in Ilfochrome printing also. So, in practice, we might want to sacrifice some shadow&highlight detail to get more contrast in these areas, so, maybe a tone scale of 2.7D or 9 stops would be quite good for a paper.
I've found that the tone scale of RA-4 paper when reversal processed is about 10-11 stops! It is definitely not too "high in contrast"; but the real problem is the curve shape.
I'll go later to these step wedge tests, but this first example is to show the tone scale problem.
So, I've found that the characteristic problems in reversal RA-4 processing are as follows:
1) Too high contrast in shadows
2) Too low contrast in highlights.
3) Cyan highlights and upper tone scale -- not particularly red-cyan crossover, because shadows are not red and cyan highlights cannot be fixed by filtration.
4) Green-magenta crossover, giving green shadows and magenta highlights.
5) Uneven extra texture in even density.
All of them give a unique look, and while they maybe cannot be solved completely, there may be and there are some tricks how they can be coped with.
I have tried the following:
- Kodak Supra Endura and Fuji Crystal Archive
First developer modifications:
- Trying different BW paper developers as first dev
- Trying different dilutions
- Adding hydroquinone to make it more active
- Adding sodium thiosulphate (hypo)
- Amount of exposure, how much is really needed.
Color developer modifications:
- Adding sulfite (Photo Engineer's tip) to reduce contrast
- Adjusting pH to change color balance
And now, to the results.
The first thing is that many of the problems are not easy to deal with; there are random variations. For example, when I look my tests, the uneven texture problem randomly appears and disappears. Sometimes it's more evident. I've found that adding hydroquinone in FD clearly decreases it but still, I have some examples without added HQ having no texture at all. Similarly, I used more than 10 hours just to try to get rid of cyan highlights by means of filtration and CD pH adjustments, just to find that it isn't crossover problem but the layer just don't develop completely. It's funny, because it's the topmost layer. Then, later, I discovered that well, suddenly I get proper whites just with enough exposure, using quite dilute developer compared to earlier experiments.
Currently I'm confused about a few things and have many directions to go to. But first, some results. I'll post more specific technical information soon.
(Sensia 100.) Some of the first experiments. Print number 25 after many modifications.
Quite good, but shows the cyan forehead problem.
First dev: Agfa Neutol 1+3 (normal dilution is 1+7) with 20% of a medium-sized hypo crystal in 500 ml (didn't have scales at that time), 3min30sec
Filtration: C17 M0 Y140 (on Fujimoto, normal neg filtration about C0 M50 Y100)
(Sensia 100) Newer experimentation with much less work.
First dev: Dektol 1+2,5 (about normal dilution), no modifications, 2min.
Filtration: Might have been about C0M50Y180.
So, as you can see, using different first developers affect greatly to the filtration!
(Velvia 50.) Experimentation with added hydroquinone.
First dev: Neutol 1+3 with huge loads of HQ (I have the amount down somewhere but it is around 30-40 g/liter!!!)
Filtration: C3 M0 Y146
Same first dev as in the previous example. Quite good. A little cyan problem and the whites could be a little more white, but if exposure is added, they go too low-contrast.
TO BE CONTINUED
PS. And, share your knowledge!!
Last edited by hrst; 11-14-2009 at 07:02 AM. Click to view previous post history.
Wow. Your prints are far better than I have ever seen. What are you using for exposure to white light? I found in my fooling around (far from experimentation) that the white light source, and the exposure made a difference. I have been meaning to try a re-exposure under the enlarger at the same exposure/fstop without a negative or any filtration. Have you tried this? I have been getting really crappy results with room lights.
"I'm still developing"
Have you tried filtering the reversal light?
I currently believe that the reversal step should be taken to completion, but I cannot say for sure if some benefits could be achieved if the reversal step would be controlled somehow. I don't see any reason now why it should. At least it wouldn't be easy. Just expose to bright room lighting at least for a minute or two, or take closer to your light source (fluorescent or tungsten), 30 seconds is probably sufficient at 20 cm (8") distance. But, it really needs quite a lot of light compared to normal exposure. 10-20 seconds of normal room light was not enough as I tested it.
Well, firstoff, there is quite a long discussion of this process at www.photo.net with myself and Bujor B among the contributors. There are examples of quite a few types of process presented including shots taken in-camera.
The first developer does indeed influence the results more than any other step. I found that Dektol 1:2 or 1:3 to be best. I even mixed a no-bromide version and experimented with bromide level. Sulfite level in the color developer is also a significant contributor to reduction of contrast. And, the curves do not match as you see. There is crossover if it is not done properly. You get cyanish highlights which means that the cyan layer in that region was not developed properly in the first developer. Bromide seems to control this to some extent.
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In your first step wedge, not enough cyan silver is developed in the first developer, and so too much dye is formed in the color developer giving a cyanish colored toe. This is probably due to the bromide inhibiting the cyan layer developing to completion, which should take place evenly in all 3 layers to make a neutral. Some silver halide solvent in the developer might help along with lower bromide.
IDK. I got a number of very nice cross processed prints, but never got a good portrait. All of my best prints were landscapes. If you see those by others, you will see that the same is probably true. It may be an unsolvable problem.
Yeah, I found that adding 0,6 g/l hypo changes the cyan problem to yellow problem . That's why I'm going to do further testing with 0,3 g/l hypo. And thiocyanate could also be tested, I bought it for this purpose.
I like these interesting color palettes. As you say, it works with landscapes quite well. It's probably because it's not always easy to get really green foliage in photographs like in paintings; trees are sometimes quite dark; but the green shadows of Reversal RA-4 print helps this! And again, magenta midtones give a nice warming effect, and finally, highlights in reflections and sky get a nice cyanish look. This is probably the best possible set of crossover problems for a landscape but certainly not for portrait, where you get magenta-brown skin and cyan forehead.
So, when I'm adding ridiculous amounts of hydroquinone, I'm probably just fighting against bromide present in developer. No wonder it helps. Maybe it would be time to scratch-mix to save some valuable HQ ...
I'll post some results, omitting many tests.
I highly recommend this process, it's really possible to get usable&interesting results. I've mainly solved problems 3 and 5 (cyan highlights and texture). Contrast also seems a bit better, but still very high. Green-magenta crossover in fact can be quite interesting in some pictures, and I think it cannot be solved completely.
Okay, what I did. Yes, I made my own first developer, a non-bromide "Dektol". I found out, however, that a little bromide is needed, and a little amount of hypo is good.
So, this is my current formula:
FD (add in this order, stirring at every step until dissolved):
Start with: Water 500 ml
Metol 3 g
Sodium sulphite 45 g
Hydroquinone 12 g
Sodium carbonate (monohydrate 80 g) (or 68,4 g anhydrous)
(I replaced 5,1 grams for bicarbonate because I haven't enough carbonate )
Potassium bromide 0.20 g (the original "dektol" type formula asks for 2 g!!)
Sodium thiosulphate pentahydrate 0.20 g
Water to 1 liter
Dilute 1:1 before using. Develop 1 min 30 sec at 23C.
Normal RA-4 dev with added sodium sulfite 0,50 g/l (0,80 g/l could be even better).
Adding more hypo increases contrast and clips highlights and shifts highlights towards yellow, and vice versa. This current value seems to give nice whites, not yellowish nor bluish, while allowing to adjust yellow filtering to get quite neutral shadows at blue-yellow axis.
No hypo, tried to balance colors. (I could select between bluish highlights or yellowish shadows)
Hypo 0,20 g/l, tried to balance colors. (Now I could select between bluish shadows or yellowish highlights). And too high contrast.
These results led me to take the hypo concentration between 0,20 g/l and 0,00 g/l: 0,10 g/l.
Decreasing bromide may give even whiter whites, but may quickly lead to very bad DMAX. I added 1/10 of the "dektol" formula's bromide and expected to see some change, but DMAX went straight to black. Well, that was the objective .
Effect of no bromide at all - unexposed sheet - should be black. The first one without hypo and the yellow one with 0,20 g/l hypo (double compared to the final formula)
Stand development (2 min 15 sec total; 45 seconds agitation first and then 1 min 30 sec completely standing) helps manage the contrast a little bit, boosting the shadows a little and restraining highlights.
http://sorsa-tv.ath.cx/~antalh/siwa-normikeh.jpg - normal
http://sorsa-tv.ath.cx/~antalh/siwa-standkeh.jpg - stand
And then, some more pictures. These are all quickly made, without bracketing exposure or filtering!
I like the green crossover, this is originally quite a dull image, I used long ago expired Agfa slide that has gone yellowish.
Ahh! The flame is not clipped.
EXPERIMENT!! It's FUN, and eventually you start getting results!
Last edited by hrst; 12-07-2009 at 11:29 PM. Click to view previous post history.