some here seem to be discussing slide transparencies and some negs. Which is the correct issue?
OH! I see RA-4, must be a neg.
Cyan should not be a problem when printing RA-4 unless you have
1. a safelight which isn't safe
2. stop bath that isn't stopping
3. fix that isn't fixing
Now I did find a very cyan problem once with a different color process, and I was dumbfounded when after weeks of chasing filters and trying to find chemistry problems, it turned out that all I needed to do was change my water from tap to distilled in my developer and stop bath. I have sinced moved the shop and no longer need to use distilled, but it was a big issue with the well water at the other shop.
Hope something helps.
I have read this many times and it always puzzles me. I have never ended up with this sort of filtration. The filtration also varies much more between individual negatives than most people say.
Originally Posted by Photo Engineer
I get good maximium black and bright white and subsequent exposures are always very consistent, so the process should be ok (Paterson photocolor RA-4 chemistry). Anyway with both Dunco and Durst colorheads I'm always printing in the range of 100Y 90M. Is this because of the lightsource (halogen) or something else like different filtration units in enlargers from various manufacturers?
I.e. Kodak Gold 200 in bright sunlight was balaced on Supra Endura with 102,5Y 92,5M. I don't have quality problems, filter values are quite far away from values other people quote.
Check to make sure the filters are moving properly in your enlarger head (assuming dichroic). I had a similar problem once and chased it for a week before a little 3in1 oil solved my problem.
I agree. I've never been able to print using either red or magenta filtration alone.
Originally Posted by ekjt
One thought ... I've found the use of shortstop (1% acetic acid) to be *essential* between color developer and bleach-fix in RA4 printing. It has been so long after that discovery, that I don't remember WHY.I seem to remember streaking, or uneven color balance or ..? Anyway, I always use it.
It was noted that NOT ALL panels of the MacBeth Color Checker were "off" - and the rest perfectly OK.
That screams to me of UV fluorescence - not a processing fault.
Ed Sukach, FFP.
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First, I'll mix fresh chemistry & try the Fuji paper again. If the same problem's there, I'll print the negative on some Kodak paper & see what happens. My filtration for Kodak is higher in magenta & yellow, so this may give me some leeway. If that corrects my problem, maybe it's the Fuji paper. If I get the same results with the Kodak, I'll try a negative I know prints fine with Kodak on the Fuji.
Kodak actually recommends using acetic acid stop bath for tray and rotary tube processing of their RA-4 papers. I have noticed that skipping stop bath causes uneven magenta streaks with Kodak Endura papers.
Originally Posted by Ed Sukach
Citric acid odourless stop bath may cause brown stains. Personally I once encountered this when trying to use Ilfostop for color processing.
Seldom if ever, do I need to include the cyan filter when printing a standard neg onto normal RA4 paper. All three filters should only be needed when adding density. One filter will always be set to zero (generally cyan), because the other two can create the same filtration of the the third.
Ed, I am assuming that you know that any amount of Cyan added to a filter pack is equivalent to an equal amount subtracted from Y and M (eg. +10c = -10y and -10m).
I always start my filter pack at 50y, 50m, 0c when printing a new neg, but I almost never finish there.
ekjt, 102,5Y 92,5M is not an unusual filter pack. if 50y,50m is a conventional starting point, 0y, 0m, 10c (the inverse of your filter pack from 50y,50m) would be far more unusual.
As I read this thread I would follow Photo Engineer's opinion as he/she appears to really know his/her poop.
To EKJT, yes I agree. It is rare to end up at exactly 50R, that is just a suggested center starting point. Starting there, you should be able to determine what is appropriate for your enlarger.
Over the years, I have found that well processed color negatives should be within a about a 10R of a central color balance for a given enlarger. The negative films from all manufacturers seem to be manufactured to rather tight speed tolerances just as much as the reversal films are.
As far as the original question goes though, I took it to mean negative to positive printing (RA) and that the filtration needed would go into the cyan, as the checker was too cyan so you have to add cyan filtrataion, or remove red to correct this problem. The initial color pack is abnormally low.
I also agree with the comment that mixed illumination in the original picture or safelight fog could give such a problem, but with the safelight you can test it with a blank piece of paper to see if it comes out cyan when you process it.
10 units of Magenta = 10yellow and 10 cyan, so your new filter pack would be:
Originally Posted by davestarr
60 yellow, 0 Magenta, 10 cyan
55y, 0m, 5c for 5 Magenta.
This filter pack indicates a strong green cast to the neg not cyan. This would be a pretty normal filterpack fo a cross proccesed (e6 material in c41 chems) E100(s,sw,vs,g or gx).
It would be interesting to know if your shadows were magenta and your highlights or midtones were nuetral or tended to be cool or green. If so I would guess that you have chemestry or some film developing issues.