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  1. #1
    Matt5791's Avatar
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    Cyan cast on print

    I was doing some RA4 printing at the weekend - I'm quite new to this, but really enjoying it.

    I was printing a particular negative. First print following test strip OK colour balance, but one area needed a little buring in.

    So second print I burned in this area with a card and a hole.

    When it comes out of the Durst Printo there is a clear Cyan cast, although nothing had been changed in the filtration and the temperatures had not changed either, infact there was only a matter of a few minutes inbetween the two prints being processed.

    Third print, Cyan cast now gone

    Any thoughts would be appreciated on what would appear to me to be a strange occurance, but I woudl guess there may well be a straightforward explanation for.

    Thanks,
    Matt

  2. #2
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    Fog, insufficient stop bath or hypo contamination on print.

    Cyan fog from a safelight is most likely if it is uniform, but streaky cyan is one of the latter two.

    PE

  3. #3
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    Thanks for that PE - I was wondering about fog - maybe I managed to fog the paper somehow, although I don't use a safe light.

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    Matt. If the process used and conditions prevailing were exactly the same on all occasions mentioned then this rules out most explanations.

    I am assuming here that the burn sequence etc on the third print which was OK was exactly the same as on the second print with the cyan cast.

    Almost suggests a faulty piece of paper as a one off but this seems unlikely.

    What paper was it?At the risk of spreading alarm and despondency which is not my intention, I have to say that I am convinced that I had a set of Fuji CA a couple of years ago which delivered a cyan cast that I couldn't filter out in most cases. Fuji very kindly replaced it for me but of course never admitted any problem. The new stuff was fine. Might have been a small batch of paper affected but I'll never know now.

    I cannot even say how many sheets were affected as I stopped after about a dozen attempts and contacted Fuji.

    If it doesn't occur again and I hope it doesn't you may never get to the bottom of it.

    It is a little unnerving of course to say the least. If I had the choice of any weapon to destroy civilised life as we know it, my vote is for unleashing constant uncertainty and the demons it spawns.

    pentaxuser

  5. #5
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    There have been known cases of one or two bad sheets in a box for one reason or another. Usually it is an accidental exposure to safelight or an accidental cutting error. I remember two sheets with a small spider pressed between them which were returned to EK so that we could "get the bugs out" as the customer expressed it.

    So yes, single or double sheet errors, or area errors can happen. A worker might use the wrong safe-flash on the moving web and fog a few square feet and then it is cut and chopped. If the web is moving they can't tell where the error is and let it go. This is uncommon though.

    At Kodak all safe-flashes are forbidden in color, or they use IR.

    PE

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    You didn't mention what enlarger and filters you're using. There are possibilities for problems there, particularly if you touched the filter dials on a color head or temporarily removed color filters. You might have set the dials to slightly different positions (possibly mis-reading something). Some enlargers have electronic controls, and it's conceivable these could malfunction. (I've seen my Philips PCS150 delay kicking in one of its three lights on rare occasion, I assume because the electronics are old and getting a bit flakey.)

    I think some of the other possibilities mentioned here are more likely explanations, at least barring additional information, but I thought I'd toss these out for the sake of completeness.

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    I have posted similar questions on this and other forums and it seems to get me no where. I have what sounds a similar set up to you, Durst printo, LPL enlarger and colorline 5000 analyser and a colorstar 1000 analyser. The problem remains for me. I can't guarantee 2 prints seconds apart will not have completely different casts. I suspect the power to my enlarger fluctuates but, I have measured the voltage continuously and re-analysed the light source on many occasions without finding any fluctuations in colour temperature etc. The process temperature of my printo is static and I have tried running prints through with massive temperature differences ie 4-5 deg C. The change seems no greater than those run through within seconds. I remain convinced that the warm up period of the enlarger light and minor voltage differences have a big effect on Modern ultra fast colour papers. I thought of a stabilized enlarger power unit but the stabilization is to within around +/- 5% much more than any voltage fluctuation I'm measuring already. I have considered a DC regulated power supply which seem to be spot on the voltage at all times but; they seem to consider the cold bulb resistance to be a short circuit,so will not power up the lamp. Please! please! any engineering type photag's, give me some ideas of what to try next.

  8. #8
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    Richard - interesting. I dont use a colour analyser yet, but I do use a DeVere 507 enlarger complete with the trans-stab unit, which I guess is a stabiliser.

    After monochrome printing, what amazes me is the speed of the paper - I commonly have exposures of around 3 - 7 seconds with an aperture of f22.

    Matt

  9. #9

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    Quote Originally Posted by Matt5791 View Post
    Richard - interesting. I dont use a colour analyser yet, but I do use a DeVere 507 enlarger complete with the trans-stab unit, which I guess is a stabiliser.

    After monochrome printing, what amazes me is the speed of the paper - I commonly have exposures of around 3 - 7 seconds with an aperture of f22.

    Matt
    Hi Matt,
    Just curious - what light source are you using? Is it a color head or are you using some other head with filters? If the latter, it's possible you are missing a piece of heat absorbing glass. When I first started RA-4 printing, I had a Beseler condenser head with color printing filters. I found the same thing as you - very short printing times even at f/22. Also, I needed a very strange filter pack - something like 5-10 Y and 5-10 M - in some cases I even needed some C filtration. Needless to say this something was wrong Turns out the problem was due to IR - I didn't have a proper heat absorbing glass. I now have a dichro color head and my printing times are much more reasonable 6-10 sec. @ f/8. and my filter pack is also where it should be. I don't know if this explains your cyan print as I would expect all your prints to have a cyan cast if this was the problem.

    Dan

  10. #10

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    Quote Originally Posted by Richard Harris View Post
    I remain convinced that the warm up period of the enlarger light and minor voltage differences have a big effect on Modern ultra fast colour papers.
    Hi Richard,
    If you suspect this - and I tend to agree with your, have you tried not using your enlarging timer to time your prints? My timer has a metronome feature, so when I print, I hold a card under the lens, start the timer, wait 10 seconds, remove the card and time my exposure by counting ticks, put the card back to end exposure, and turn off the enlarger. It might be worthwhile for you to try this.

    Dan

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