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  1. #1

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    Pyrocat HD and Tmy

    Hello everyone. I've been wanting to try Pyrocat and 4x5 Tmax 400 but I can only find development times for use with tubes. I pretty much do all my developing in tanks and sometimes trays does anyone have a good start time for tanks with normal agitation?
    I've read that TMY in Pyrocat has an effective film speed slighty higher than 400, is this true or should I start my tests at around 400.
    Also I will be using a cold light enlarger for contact prints (switching to 8x10 once I finish the test) Thanks for your help.

  2. #2

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    My starting point for Kodak TMY 400, rated at EFS 400 is Pyrocat diluted 2:2:100, semi-stand developed in a tray (a slosher) for 16.5 minutes at 71 F. Semi-stand agitation: 20 seconds of gentle agitation intially, followed by 5 seconds of gentle agitation at the 8 minute (half-way) point. For minimal agitation (5 seconds gentle agitation per minute) reduce the development time by 30%.

    I have plotted the D Log E curve for the semi-stand condition I described if you are interested.
    Tom Hoskinson
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  3. #3

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    Quote Originally Posted by Tom Hoskinson
    My starting point for Kodak TMY 400, rated at EFS 400 is Pyrocat diluted 2:2:100, semi-stand developed in a tray (a slosher) for 16.5 minutes at 71 F. Semi-stand agitation: 20 seconds of gentle agitation intially, followed by 5 seconds of gentle agitation at the 8 minute (half-way) point. For minimal agitation (5 seconds gentle agitation per minute) reduce the development time by 30%.

    I have plotted the D Log E curve for the semi-stand condition I described if you are interested.
    Tom,

    I would be interested in looking at your plot of Tmax 400 and Pyrocat-HD with these conditions. My own semi-stand development of Tmax 400 is based on a dilution of 1:1:150 so I would be very interested in comparing curves.

    Sandy

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    Quote Originally Posted by sanking
    Tom,

    I would be interested in looking at your plot of Tmax 400 and Pyrocat-HD with these conditions. My own semi-stand development of Tmax 400 is based on a dilution of 1:1:150 so I would be very interested in comparing curves.

    Sandy
    Sandy, the plot and data is in a MS Excel file in my lab computer. I can email it Monday. I used a Macbeth TD 504 color densitometer and recorded the "all" channel and the blue channel data.
    Tom Hoskinson
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  5. #5

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    Tom, thanks. I also would be interested in the plot of Tmy for semi stand agitation. Any info I can get on this is greatly appreciated.

  6. #6

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    Quote Originally Posted by PhotoBulley
    Tom, thanks. I also would be interested in the plot of Tmy for semi stand agitation. Any info I can get on this is greatly appreciated.
    I sent the Excel file to you and Sandy as an email attachment. I suppose I could also have attached it to this message as a PDF file.
    Tom Hoskinson
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  7. #7

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    I have attached a PDF version of my TMY/Pyrocat Excel File (I hope).
    Attached Files
    Tom Hoskinson
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  8. #8

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    Thanks again Tom, this is very helpful. I ordered some pyrocat today and can't wait to start shooting.

  9. #9

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    Quote Originally Posted by Tom Hoskinson
    I have attached a PDF version of my TMY/Pyrocat Excel File (I hope).
    Thanks. For your interest I am attaching a family of curves of TMY in Pyrocat-HD 1:1:150 and developed with extreme minimal agitation. The meaning of the numbers on each line are as follows: 1) Development time (multiply by 10X), 2) Effective Film Speed, 3) CI or contrast index, and 4) SBR, where 7 is considered normal and equivalent to N.

    The SBR values as given are based on a desired negative density range of 1.55 for printing on AZO #2 papers, and the readings were made with the blue channel of a color densitometer.

    Sandy King
    Attached Thumbnails Attached Thumbnails TMYPYROCAT.jpg  

  10. #10

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    Quote Originally Posted by sanking
    Thanks. For your interest I am attaching a family of curves of TMY in Pyrocat-HD 1:1:150 and developed with extreme minimal agitation. The meaning of the numbers on each line are as follows: 1) Development time (multiply by 10X), 2) Effective Film Speed, 3) CI or contrast index, and 4) SBR, where 7 is considered normal and equivalent to N.

    The SBR values as given are based on a desired negative density range of 1.55 for printing on AZO #2 papers, and the readings were made with the blue channel of a color densitometer.

    Sandy King
    Sandy, I tried the semi stand development and your curves confirm my first impression. It seems that for extended development and even for the "normal" development the b+f is quite high. Has this been a problem with your pt/pd printing and lenght of exposures?

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