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  1. #1

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    Kodak Portra Black & White Paper, RA-4 / getting heavy magenta cast

    I ran acros a box of old expired Kodak Porta Black & White paper, but for $6 bucks I decided to give it a try.
    no matter what I tried , I kept getting a magenta cast while printing a contact sheet. Today I decided to go on and try to print the first picture regardless. I printed a strip of 2 sec steps (2-4-6-8sec) and to my suprise, very good black and white tones. I was happy and found my perfect exposure at F16 for 7 sec. What do I get a horrible and quite heavy magenta cast. So I thought maybe cause I am reusing the developer. So I tried a fresh batch of developer. Horrible magenta cast. I tried changing the exposure to F11-3.5sec just in case (shouldnt matter but I had to try), I get horrible magenta cast. what gives ? what is causing this magenta cast. I originally thought maybe 'cause the paper was expired, but that one test strip came out perfect...
    I duplicated exact temperature, process time and Filter pack I had used during the test trip. nothing,: I get magenta cast. I don't get it ?

    thanks for any ideas.

  2. #2

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    So just to summarise: You get a magenta cast when contacting all the negs on a contact sheet of paper when presumably using the white light from the enlarger?

    You get a perfect print using a test strip at f16 and 7 secs but the same magenta tone returns when you use the same over all exposure with F11 and 3.5 secs. When doing the test strip did any of the other exposure such as 2,4, 6 secs etc have the magenta cast or were they all free of the cast?

    Everything else about your process was identical with both the magenta cast prints and the perfect prints?

    If all of the above is correct then I don't get it either. Are you sure that it was exactly as I have summarised and is my summary correct?

    Thanks

    pentaxuser

  3. #3
    cjbecker's Avatar
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    Yea I dont get it either. Is it the same magenta cast as if you left the paper out in the light for a long period of time?

  4. #4
    Thomas Bertilsson's Avatar
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    Does the Portra RA-4 paper require color correction like the more normal color RA-4 papers do?
    "Often moments come looking for us". - Robert Frank

    "Make good art!" - Neil Gaiman

    "...the heart and mind are the true lens of the camera". - Yousuf Karsh

  5. #5

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    One more question: What were the filtration settings, if any, when doing the contact sheet or was it simply white light and did anything change when doing the test strips? I just cannot work out what had changed to produce a neutral print at f16 and 7 secs and a cast at f11 and 3.5 secs.

    The only changes I can see is that the contact sheet was one sheet, the perfect print test sheet was another sheet and the same exposure print on which the cast re-appeared was a third. So bad sheet, good sheet, bad sheet???? Makes no sense

    We need this OP to read our posts and respond. We can speculate until the cows come home otherwise

    pentaxuser

  6. #6
    Mike Wilde's Avatar
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    I have a few hundred feet of a 12" roll this suff, long expired languishing in my freezer.

    You can tune the contrast range by tweaking the filitration.
    It is designed to be only moderately filtered if you are exposing a C-41 negative, is the masking in the neg does most of the heavy lifting. +/- 50R off of a base of 50R I seem to recall is how my stuff works now.

    Yes, I get a magenta cast in al image elements, and even a slight one in the all white areas of the print all the time with this stuff. It can suit some images. That is why this stuff came with an expiry date.
    I have not had any sucess gettign rid of this cast.

    I use the paper mostly to catch up on contact printing back logged b&w fnegative filer pages when I otherwise have the ra-4 roller processor fired up to print colur work.
    my real name, imagine that.

  7. #7

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    Here are all the answers:

    - Yes , I was getting a magenta cast when printing contact sheet with white light from the enlarger.
    - I dont get a perfect print when printing for 7sec @ F16 I get a heavy magenta cast.
    - When I did the test strip at 2-4-6-8 sec , I did not get a magenta cast. all steps are free of magenta cast (weird)
    - yes, everything was identical about the prints with cast vs. the strip test without cast. (filter pack had not changed)
    - the piece that I used for the strip was cut from a sheet, when I used the second half of the same sheet I got a magenta cast (so the theory of the one good sheet, several bad sheets also does not hold)
    - your summary is correct.
    - Filter pack was 55M 45Y when I printed the test strip that came out with no color cast. so without changing filtration I printed the full print for 7 sec @ F16. I got the magenta cast... (weird)

    - I did not leave the paper out, guaranteed.

    - yes, the portra Black & White (this is a black and white chromogenic paper) does require filter correction but behaves different than the normal color RA-4 such as endura. I read in publication g4006 that filtration depends on what type of film you are trying to print from. (it has several starting points depending on the film). For my case I was printing from BW400CN which is also a chromogenic black and white C-41 film. So in other words, I was printing from C-41 chromogenic black and white film onto Portra RA-4 also chromogenic black and white. So I used both suggested starting points on the publication. always magenta cast.

    I hope to have answered all the questions. I did further testing last night, I will post the findings later to see if they make sense to anyone.

  8. #8
    Thomas Bertilsson's Avatar
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    As Mike Wilde has stated above, it is probably a thing of the paper having aged unfavorably.
    "Often moments come looking for us". - Robert Frank

    "Make good art!" - Neil Gaiman

    "...the heart and mind are the true lens of the camera". - Yousuf Karsh

  9. #9

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    Actually to Mike (since you have this expired paper like me) and everyone. I am happy to report that I was able to get rid of the magenta cast. With repeatable results. Actually getting good black and white tones perhaps not as neutral as orthochromatic but within workable results to make the paper usable.

    Please note that no matter what filtration I would use, I was always getting the same heavy deep magenta cast . So I never thought the filtration had to do with the problem as the magenta cast never changed. I am not an expert chemist in anyway so forgive if I don't know what actually solved the problem but here is what I did.

    - I went and read the publication again g-4006 . this is the exert that lighted the bulb in my head.

    [FONT=Times New Roman][SIZE=2][FONT=Times New Roman][SIZE=2]
    Processing conditions may affect the color (hue) ofPORTRA Black & White Paper. You may see a hue changeon the magenta/green axis due to variations in developer tankactivity and pH. Low developer activity and/or pH (typicallysevere oxidation and/or under-replenishment) will cause ashift toward a green hue. High developer activity and/or pH(usually over-replenishment) will cause a shift toward a
    magenta hue.
    [/SIZE][/FONT][/SIZE][/FONT]
    this is what I did as I figured this would lower developer activity... (I dont know how to check or modify pH)

    - pre-wash 3 times until water came out fairly clear.
    - I further diluted the developer by adding more distilled water to the working solution.
    - I further diluted the stop bath , I figured this would reduce the acid.
    - instead of using motor agitation, I did manual rotation (much slower) by hand .
    - and what I believe to be most important; I lowered the developer temperature to 74F increasing the processing time from 45sec to 2 min.

    voila, now every print comes out with no magenta cast, I mean none , zero. no color cast whatsoever. The interesting thing is that when the print would come out with the magenta cast, the stop bath would be dark bluish , but when prints come out without the cast, the stop bath would be pink. I wonder what happens in there....??

  10. #10

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    Glad you have solved the problem but what seems still inexplicable and may remain that way is why in what I assume to the same timescale i.e. done consecutively you got a neutral print. I had a look at he same Kodak publication and there is nothing even hinting at your steps as a means of curing the problem

    So like you I am still puzzled as to the cause of the problem.

    pentaxuser

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