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Thread: Dark Streaks on RA4

  1. #1

    Dark Streaks on RA4

    Hello! First post on the forum. Click image for larger version. 

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    Iíve been doing some color printing this week and have been getting these streaks on various prints. It doesnít happen every print, even ones processed in the same hour or so. Iíve done the 10 minute sit in total darkness to look for any leaky light in the darkroom. Also itís happened on my 8x10 and 16x20 prints, so it doesnít appear to be a paper fault. There also seems to be a consistent curve of the line towards one end of the print, and it does run the same direction of the length of the print drum. Chemical related?

    Also could be a total coincidence, but does anyone know if RA4 reacts with copper or brass? My wedding band is a combination of the two, and the times Iíve remembered to remove it SEEM to align with prints that didnít have the streak. But I canít find anything supporting that theory.

    Hereís the setup/process

    Jobo cpa2
    Jobo 4541 drum (8x10)
    Jobo 4561 drum (16x20)
    Arista Ra4 kit
    Fuji CA Paper
    Develop and blix at 85F for 3 min each
    Streak is there by the time I open drum to wash print


    Thanks in advance! Everything post Iíve perused up to now has been incredibly helpful - from purchasing my 4x5 camera to proper sheet film developing.

  2. #2

    Re: Dark Streaks on RA4

    Not sure why image is upside down...it isn’t on my phone. Oh well, streak still visible

  3. #3
    Ironage's Avatar
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    Re: Dark Streaks on RA4

    I looks very chemical like to me. Do prints where you didn’t make a test strip have similar lines? I don’t think that the ring would have any effect that would show up along the entire print edge. It is almost like the chemicals flow into the drum reach the back and produce a wave back. Really strange...

  4. #4

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    Re: Dark Streaks on RA4

    It looks like you may not be using enough chemistry in the drum. If you don't use enough, then you will get uneven coating of the developer on the paper. Another related issue is that the paper isn't flat against the drum surface, which causes the paper to not be fully submerged in the developer.

    Try increasing the amount of developer used in the drum to see if the problem goes away.

  5. #5

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    Re: Dark Streaks on RA4

    Are you using a paper safe ?? I've been burned by the clam shell type. The latch can cock open the lid. It does look like chemistry.

  6. #6

    Re: Dark Streaks on RA4

    Thanks everyone for your insights.

    My smaller drum didn’t list solution minimums, but I was able to determine somewhere online that it needs min 60ml for a 8x10. Large drum requires min 180ml. I use 250-300ml for the small or big drum. I also had to level my jobo on the new table it’s on, because I was getting missed spots on far edge of my prints due to the tilt.

    The issue does occur on regular prints. Both in 8x10 and 16x20. They’re also in separate paper safes, and the 16x20 is in a dark bag.

    . If a drop of water were to run down the dry paper pre-development, could that alter the developing stage at all? I try to dry my drums thoroughly between prints, but I do get lazy sometimes and skip fully detaching the reservoir on the lid to dry the inside fully. I can only imagine it would be fresh water because I do rinse the drums thoroughly between prints to flush out any remaining blix.

  7. #7
    John Olsen
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    Re: Dark Streaks on RA4

    I used to get these if a dribble of water ran down the sheet before I poured in the chemistry. It meant I hadn't dried out the drum well enough from the previous sheet. Maybe this is your case?

  8. #8

    Re: Dark Streaks on RA4

    Quote Originally Posted by John Olsen View Post
    I used to get these if a dribble of water ran down the sheet before I poured in the chemistry. It meant I hadn't dried out the drum well enough from the previous sheet. Maybe this is your case?
    I think this is probably the most likely, and helpful to verify this has happened to others! Thank you!

  9. #9
    Andrej Gregov
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    Re: Dark Streaks on RA4

    I process 16x20 and 20x24 RA4 prints in a CPP3 with 3063 drum. I have seen similar streaking on some prints (usually places with highlights like skies) which is caused by the developer coming into contact with the Blix and causing a stain. I would add a 30 second wash step in-between your developer and Blix stage and that should fix it.

    With regard to other notes you posted, I'm not familiar with your drum numbers. But your chemistry sounds too low. If you see the Print Drums section below in Jobo's documentation, you'll note that 8x10 drums require at least 100ml of chemistry and 16x20s 200ml. I usually double these amounts for my own work to get adequate coverage. Remember, you can replenish your developer after every run to maintain its strength. See Fuji's documentation for replenishment rates if being color correct between print runs is important. Otherwise, you will have slight magenta wandering (less) between run to run.

    http://www.jobo-usa.com/images/manua...capacities.pdf

    With regard to comments needing to dry the drum in-between runs, this is not necessary in my experience. Simply empty the drum of any remaining water after your run, load your new print, then before you begin your next run on your Jobo, do a water pre-rinse. So, it will resemble:

    30s Pre-rinse > 1m developer > 30s rinse > 1m Blix > x 3-6 rinses to clean the print/drum

  10. #10

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    Re: Dark Streaks on RA4

    Kodak recommends the use of ordinary stop bath to reduce the staining. As A.G. mentions here, developer and blix can cause a stain. I've used stop with RA4 forever. You can use water as well. Tube processing is vulnerable to this problem.

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