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  1. #1

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    Cause of green streaks in RA-4 prints?

    Hi,

    I've finally acquired the final item I needed to begin color print processing (a Beseler print drum, bought via this eBay auction, if anybody cares). So today I tried my hand at it, using the chemistry and processing steps described here. Most of my prints came out OK -- or at least, the problems were obvious ones of exposure or color balance that I could correct. About 1/4 of the prints, though, have an odd green streak down the center, as shown in this example. I've tried Googling and searching the archives here but haven't found an explanation. My best guesses at this point are stray bits of water dribbling on the print before processing begins and improper coverage of the print in developer or another chemical. (I tried quantities of 75ml-100ml in my drum, but I'm really not certain what the correct amount is.) Any advice is appreciated. Thanks!

  2. #2
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    It may be that the drum or cap was not dry and a small trickle of water or dilute blix ran across the paper before development. If it were just water I would say that it is not the most likely source of your problem because the paper tolerates a prewet with no big change taking place. It is probably water with some contaminant such as blix or stop.

    For an 8x10, about 100 ml should be more than enough in a 2 print drum. If the coverage of developer over the paper is not fast enough, you can get a streak like that on the print opposite (highest) from the addition point if addition and rotation are slow or if rotation is not complete.

    Improper prewet could also do this.

    Lack of a stop bath or bad blix usually gives darker greeinsh or bluish streaks, not lighter ones.

    PE

  3. #3
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    I had a similar problem of streaks using the EP2 processing system, which pre-dates RA4.

    The problem I had was with the pre-wash creating Cyan streaks, very similar to yours.

    The solution was to discard the pre-wash, which is really about getting the temperature of the paper and drum up to speed.

    Instead I used 250ml of developer which has enough bulk to stabilise the temperature of the drum and paper, as well as overcoming and problems of not enough solution.

    After processing each sheet of paper I pulled the correct amount of used solution out and and added fresh solution in it's place.

    I never had a problem after that.

    I was using a Jobo but the mechanics are very much the same.

    Hope this helps.

    Mick.

  4. #4

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    Quote Originally Posted by srs5694
    Hi,

    I've finally acquired the final item I needed to begin color print processing (a Beseler print drum, bought via this eBay auction, if anybody cares). So today I tried my hand at it, using the chemistry and processing steps described here. Most of my prints came out OK -- or at least, the problems were obvious ones of exposure or color balance that I could correct. About 1/4 of the prints, though, have an odd green streak down the center, as shown in this example. I've tried Googling and searching the archives here but haven't found an explanation. My best guesses at this point are stray bits of water dribbling on the print before processing begins and improper coverage of the print in developer or another chemical. (I tried quantities of 75ml-100ml in my drum, but I'm really not certain what the correct amount is.) Any advice is appreciated. Thanks!
    It's not often that I have seen anybody who has posted on an identical problem to mine but this is it.

    The good news, if my experience is anything to go by, is that it will be very rare but of course it is always disconcerting when it happens at the beginning of your time in colour printing.

    The bad news is that I can't say what the reason was in my case but I strongly suspect it was not drying the inside of the drum before inserting the next print. I think that water left in the drum streaked the print just before the developer got to work. There may be others with chemistry knowledge who can confirm that a water streak will turn green in the circumstances stated. I have never seen another colour.

    If I re-call things it happened when I was in a rush to do prints to take with me to a family get together. It hasn't happened for several months now.

    These days I check the drum carefully to ensure that the cloth has fully dried the drum. Incidentally if I had produced a print as good as your example at the start of my colour printing, ignoring the streak of course, I'd have been very pleased. You've certainly done better than I did.

    Pentaxuser

  5. #5

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    Thanks for the suggestions. It could very well be a trickle of water or even a bit of blix; I've only got one drum and was doing prints in quick succession, washing and drying the drum between prints. Any tips on quickly drying the drum and its cap to avoid this problem? I tried using a hair dryer, but it didn't seem to be doing quite a complete enough job.

    I'll also look into the pre-wash, but the placement of these streaks is suspicious; all three affected prints have a single streak right down the middle of the print. If the pre-wash were causing problems, I'd expect a more even pattern of streaks -- or did you get a single streak with your pre-wash problem, Mick?

  6. #6

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    Quote Originally Posted by pentaxuser
    Incidentally if I had produced a print as good as your example at the start of my colour printing, ignoring the streak of course, I'd have been very pleased. You've certainly done better than I did.
    Thanks for the compliment. As it happens, the actual print has a bit of a cyan cast to it, but VueScan (which I used to scan the print) corrected that. Aside from the streaking, though, I'm pleased with my first foray into color printing.

  7. #7

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    Quote Originally Posted by srs5694
    Thanks for the suggestions. It could very well be a trickle of water or even a bit of blix; I've only got one drum and was doing prints in quick succession, washing and drying the drum between prints. Any tips on quickly drying the drum and its cap to avoid this problem? I tried using a hair dryer, but it didn't seem to be doing quite a complete enough job.

    I'll also look into the pre-wash, but the placement of these streaks is suspicious; all three affected prints have a single streak right down the middle of the print. If the pre-wash were causing problems, I'd expect a more even pattern of streaks -- or did you get a single streak with your pre-wash problem, Mick?
    For what it is worth, it certainly wasn't pre-wash in my case. I don't use one. I am pretty certain it wasn't dilute blix either as the one thing I do use is two 30 second rinses and then once the paper is moved to a brightener/stabiliser I then rinse the drum again. I only ever had one streak on any streaked print.

    Mine is also a Jobo drum. It is the bottom that tends to retain water as it has a lower well in the middle of the bottom of the drum. I use a cloth that you use for drying dishes but one which is made of towelling material as it absorbs water better than say cloths made of linen or close weave cotton.

    Pentaxuser

  8. #8
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    Just a thought, but sprinkle some water on a sheet of lightly fogged paper and then process it as you usually do.

    If you get light cyan or green spots where you splashed the water, then that pretty much proves that there is a water problem.

    It will cost you one sheet of paper and one process run.

    PE

  9. #9

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    I use a prewash all the time. It helps cure the green meanies. OTOH a slightly wet drum. Just drops of water will cause stains. Drove me NUTS. I now have multiple drums and a big roll of paper towels. No drum gets reused until it's wiped dry. Lid. You name it.

  10. #10
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    I just had a look at my streaked print on my darkroom wall. The streak(s) look like forked lightening.

    So they are not quite like yours.

    Mick.

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