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  1. #1
    Shinnya's Avatar
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    Pyrocat: almost no stain

    Hi,

    This may be better directed to Sandy, but I will post here for the future reference. Today I mixed another butch of A solution. When I looked the plastic container of catechol, it was rather dark inside. I went ahead and mixed the solution anyhow.

    I just processed the first set of 4x5 films, and they seemed to be developed OK but do not have stain almost at all. The other thing I noticed was the color of developer once used. It usually has brownish color to it, but it was rather yellow this time.

    Does anyone have an explanation for this? Thanks for your help.

    Warmly,
    Tsuyoshi
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  2. #2
    Leon's Avatar
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    are you using a different film to your usual? I find some films stain REALLY well (delta 3200, HP5) and on others the stain is virtually not visible (FP4+). ditto for the colour of the used developer - it depends on the film

  3. #3
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    Not sure what the answer is, but how old was the catechol? I'm wondering about the keeping properties of this chemical and proper storage. Does it make sense to buy enough to store and have around, or will it lose its potency over a relatively short time? Would freezing affect this storage time? tim

  4. #4

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    Tsuyoshi,

    Do you have a densitometer? If so, measure highlight density in Visual and Blue mode. The differenece between the two is stain density, whether or not it is visually apparent. Pyrocat-HD stain can be visually deceptive because at times it can appear almost neutral in color.

    The fact that the used developer is yellowish is a good rather than bad sign because it shows that the solution did oxidize very much. Since oxidation is one of the main causes of B+F (general) stain I see this as a positive. The yellow color of the user developer is consistent with my own work when I develop 120 film in tank with minimum agitation. On the other hand, when developing a sheet of 4X5" film in a tube with only 75ml of solution and constant agitation, the color of the used developer is much darker, say like dark tea.

    My opinion is that your pyrocatechin is still in good shape. If it were not the color of the used developer would likely have been a very dark brown, or even black.

    Sandy







    Quote Originally Posted by Shinnya
    Hi,

    This may be better directed to Sandy, but I will post here for the future reference. Today I mixed another butch of A solution. When I looked the plastic container of catechol, it was rather dark inside. I went ahead and mixed the solution anyhow.

    I just processed the first set of 4x5 films, and they seemed to be developed OK but do not have stain almost at all. The other thing I noticed was the color of developer once used. It usually has brownish color to it, but it was rather yellow this time.

    Does anyone have an explanation for this? Thanks for your help.

    Warmly,
    Tsuyoshi
    Last edited by sanking; 11-25-2005 at 12:06 PM. Click to view previous post history.

  5. #5
    Shinnya's Avatar
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    Hi,

    I think I should be a little more specific about my explanation...

    So far, I have only used FP4 (Arista Pro and Defender soon) for 4x5 work, though it is not that I shoot a lot with 4x5. I have processed films from the same box about three months ago (that is how often I use 4x5...), and they had an obvious brown stain to it. Also, the edge is a little more pinkish than what I got last night.

    I personally have never seen any other negatives developed in Pyrocat than mine, so I cannot tell what they usually look like (or should look like). So, I just took pictures of the different things that I am talking about.

    First is the color of developer. This yellow one is from processing FP4, and the other one is used water stop (after development). After posting this message, I processed 8x10 Tri-X which I use a lot, and the color of the developer was as usual.

    The next one is the color of the container which has catechol (next to Tartaric Acid). The darker stain is very apparent.

    I processed some more films today, and 4x5 FP4 come out just like ones that I got in the first place. Then I processed Tri-X, and they seemed to be normal (maybe a little less stain than my normal).

    Now, I start wondering this particluar one is how it should be and maybe ones before this batch had too much stain so to say. Here's the comparison on a light table. The negatives on left are previously developed, and ones on the right is from last night.

    I do not have a densitometer, so I cannot tell for sure, but ones from today seemed to have a less general stain, and the it has a pinkish base to it. The others have a very clear base.

    Does anyone have a good explanation for this? Thanks again.

    Warmly,
    Tsuyoshi
    Attached Thumbnails Attached Thumbnails solution.JPG   catechol.JPG   negatives.JPG  
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  6. #6
    kunihiko's Avatar
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    Hi
    I have no idea of what's going on your FP4+, waht I only can tell is that negs on left look like what I normaly get from Pyrocat-HD.
    Can you bleach a neg to see how dense the stain is ?

  7. #7

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    you can look at the stain in photoshop. scan the negative in color and compare the channels.

  8. #8
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    No explanation, but how do they print? I think this may be the real test, since there is no densitometer available. tim

  9. #9
    Shinnya's Avatar
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    Hi everyone,

    To tell you the result first, they both do print fine. At least visually to my eyes. My issues is that they look so different even though they are from the same box of film. It is quite true that like Sandy said (well after all he is the one who came up with this) the stain can be very deceptive, I must say.

    This was fourth batch of Pyrocat that I made so far. This time it looks quite different in terms of the color of stain. So, I was wondering if I did anything so different when I mixed the developer this time (well the only things is that I heated it to 60 degree in celsius before I put any chemicals).

    Again, they do print fine. So, I guess they are OK...

    Thanks for all of your comments though.

    Warmly,
    Tsuyoshi
    Attached Thumbnails Attached Thumbnails contact.jpg  
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  10. #10

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    I wish I had an absolute explanation for this but I don't. However, the negatives on the left have a lot of stain and the ones on the right do not, so if this is the same film I suspect you mixed the formula differently.

    However, I suspect that nothing is wrong with your pyrocatechin and phenidone since the negatives appear fully developed, and this would not have happened if either of the reducers was bad.

    I am going to go out on a limb and suggest that you may have added too much of the sodium metabisulfite in mixing the stock solution. The amount of sodium metabisulfite in the formula is quite critical to the formula: too little and the developer is slightly less energetic, too much and it becomes more active but the stain is lost. If by any chance you happened to increase the amount of metabisulfite by a factor of 3X-5X I am fairly certain that would be enough to kill the stain. It would also make the developer more active.


    Sandy


    Quote Originally Posted by Shinnya
    Hi everyone,

    To tell you the result first, they both do print fine. At least visually to my eyes. My issues is that they look so different even though they are from the same box of film. It is quite true that like Sandy said (well after all he is the one who came up with this) the stain can be very deceptive, I must say.

    This was fourth batch of Pyrocat that I made so far. This time it looks quite different in terms of the color of stain. So, I was wondering if I did anything so different when I mixed the developer this time (well the only things is that I heated it to 60 degree in celsius before I put any chemicals).

    Again, they do print fine. So, I guess they are OK...

    Thanks for all of your comments though.

    Warmly,
    Tsuyoshi
    Last edited by sanking; 11-26-2005 at 01:04 PM. Click to view previous post history.

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