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Thread: +/- Development

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    Bruce Osgood's Avatar
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    +/- Development

    Suppose a scene has a 6 stop contrast range and your (B/W) film has what you feel is a 7 stop contrast range; do you ADD 1 stop development to stretch the scene to 7 stops OR do you MINUS 1 stop development to compress the film to the scene? Seems to me you would ADD 1 stop but I thought I'd better ask.

    Secondly, is there a universally accepted % amount of time to ADD or MINUS development time? Such as add/minus 15% adjust 1 stop, 25% for two stops, etc. or is this too something one determines with there own materials?

    TIA,

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    "Suppose a scene has a 6 stop contrast range and your (B/W) film has what you feel is a 7 stop contrast range; do you ADD 1 stop development to stretch the scene to 7 stops OR do you MINUS 1 stop development to compress the film to the scene?".

    Add (i.e. N+1 for instance).

    "Secondly, is there a universally accepted % amount of time to ADD or MINUS development time? Such as add/minus 15% adjust 1 stop, 25% for two stops, etc. or is this too something one determines with there own materials?"

    There are some guidelines which can be used as a starting point (i.e. the percentages you mentioned) BUT further testing is necessary because not all film-paper-dev combinations react to the same increases and/or decreases in dev time. In addition, as the contrast range of the scene moves further aways from normal, for example N+2 and more or N-2 and less, dev time changes become less linear and even in some cases displays exponential even cubic increases or decreases.
    Francesco

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    lee
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    Bruce,
    If I understand your question you would need to clarify for me which system you are going to use. Francesco uses the BTZS and I can not speak for that. In your example, in the zone system a normal scene would have 5 zone that you might consider (from z III to z vII). I would give one stop more of exposure and one stop less development (n-1) to bring the highlight down into the z vII range. As to how far, tests should be run to see how much or less development is needed to move the zones in each direction. The most accurate way is to measure with a densitometer.

    lee\c

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    Bruce,

    you could indeed use N+1 (prolonging dev. time) to expand the contrast.
    OTOH it would be interesting to know what format you use, as for 35mm you can as well use a higher paper grade. Maybe not exactly the same result als the curves of film and paper are not the same, but by extending dev. time for 35mm you just add grain to the negative.

    Starting figures: 1 stop expansion(contraction) for classical emulsions: +(-)20-30% dev. time; for T-grain films: +(-)10-15%. As stated above, this needs thourough testing for reliable and reproductable results!

    Jan
    Jan

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    Bruce Osgood's Avatar
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    I was thinking in terms of 4 X 5 BPF 200 @ 200 and developed in trays using PMK.

    That's more specific than I intended, I was just looking for direction in terms of shifting Contrast Range to meet a films potential at the development stage.

    As I now understand it, a scene with more range/stops than a films capacity should receive less development which would equal the films range. ie: a scene of a ten stop range would get -3 stop development IF the films range was 7 stops. I realize there are other means to deal with such a scene like camera exposure, pre-exposure, Neutral Density filters and perhaps many others.

    So it is written, so it shall be: You can/should/could/would adjust development time to MEET, not exceed or fall short of your films proven contrast range. -- Providing you're using 4X5 in a tray.

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    lee
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    Bruce,

    BPF 200 is probably not able to do much more than N+1. It doesn't build contrast to well and may not be an appropraite choice of film for those less than normal contrast scenes. Just my opinion gleened from what I have read and seen from Don Miller who has a lot of experience with that film.

    Some say that local contrast is more important than overall contrast and some believe if you N- development will reduce said local contrast and the print will not "glow". This is an individual choice. Some experience is needed to judge this. You can find a lot of information about film developing in Ansel's #2 book The Negative.

    lee\c

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    Quote Originally Posted by Bruce (Camclicker)
    I was thinking in terms of 4 X 5 BPF 200 @ 200 and developed in trays using PMK.

    I would not recommend PMK for BPF with N+ development. A normal development time foir BPF with the 1:2:100 dilution of PMK for N scenes is around 7-8 minutes at 72ºF with rotary processing. To do N+1 would require a time of develoment of over 20 minutes at the same temperature. You need to add about 20% more time for tray development.

    Your best bet if you plan to expose a lot of BPF in situations that require N+ development is to switch to another developer such as Rollo Pyro 2:4:100, Pyrocat-HD 2:2:100 or a 1:100 dilution of the new Pyro-TEA developer I just introduced on another thread on this forum. These formulas will allow N+1 develoment times with BPF in about 9-10 minutes, and at best about N+1.5 at about 16 minutes.

    Sandy
    Last edited by sanking; 12-19-2004 at 12:10 AM. Click to view previous post history.

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    Bruce Osgood's Avatar
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    Thank You

    Francesco, Lee, JanT and Sandy,

    thank you for sharing your insights, I appreciate it very much.

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    I can speak for the 2:2:100 in pyrocat HD that sany talks about. And I have never gotten BPF beyond N+1. But when you get into the SBR BPF likes it sure is pretty. At least in my opinion.
    Technological society has succeeded in multiplying the opportunities for pleasure, but it has great difficulty in generating joy. Pope Paul VI

    So, I think the "greats" were true to their visions, once their visions no longer sucked. Ralph Barker 12/2004

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    Quote Originally Posted by mark
    I can speak for the 2:2:100 in pyrocat HD that sany talks about. And I have never gotten BPF beyond N+1. But when you get into the SBR BPF likes it sure is pretty. At least in my opinion.
    BTW, my comments about getting N+1.5 at about 16 minutes apply only to silver gelatin printing. There is no way, short of a miracle, that you could get to N+1.5 for AZO#2 with BPF 200.

    Printing with alternative processes is another matter because of the high actinic filtration of the Pyrocat-HD stain, which increases contrast dramatically with UV sensitive processes. With the recent BPF I have tested, based on a required DR of about 1.75 for pure palladium printing, I can get down to N+1 (or SBR 5.5) with about 10 minutes of development, using Pyrocat+ 5:3:1:100 . Pyrocat+ is same as Pyrocat-HD with the C solution being a 1% solution of ascorbic acid.

    Sandy
    Last edited by sanking; 12-19-2004 at 12:14 AM. Click to view previous post history.

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