pushing time shorter than normal time?

Discussion in 'Darkroom Developing and Printing' started by Steven Woody, Jul 15, 2006.

  1. Steven Woody

    Steven Woody Guest

    i noticed in Kodak's TMX data sheet, it says that normal development
    time for D76 is 7 1/4 min, for pushing to EI200, it is 6 1/2 min. i
    can not understand this.
     
    Steven Woody, Jul 15, 2006
    #1
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  2. Which data sheet is this? I am looking at F-4016 January
    2002 which is I think the current one. It gives 6-1/2
    minutes for both speeds, small tank, 68F. This is in line
    with Kodak's claim that T-Max films can be underexposed one
    stop wtih no adjustment in developing time.
    I see 7-1/4 minutes at 68F using D-76 for large tank
    processing of T-Max 100 at normal speed but the push
    processing charts for large tanks do not show D-76 at all.
    Check the data sheet for its number and date, I have some
    of the older ones too, and also tell me which charts you are
    getting the data from.
    Note that Kodak has made misprints in the past.
     
    Richard Knoppow, Jul 15, 2006
    #2
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  3. Steven Woody

    Steven Woody Guest

    that doc i mentioned is in my office and i can not touch it now. but i
    just checked the F-4016 in my home computer, i found the devlopment
    time in the doc are all 9 mins for normal speed and EI200 pushing, it
    still differ with what you said. this version is F-4016, March 2002.

    -
    woody
     
    Steven Woody, Jul 15, 2006
    #3
  4. Are you sure you have F-4016 and not F-32? The 9 minute
    time is given in F-32, which is the data brochure for the
    old T-Max, the web version is dated March 2002 because of a
    notice of the discontinuance of the film. The latest edition
    of F-4016 is dated February 2002. I am not sure what
    revisions were made to the edition I had but the times for
    the new T-Max are the same.
    A change from 9 minutes to 6-1/2 minutes is substantial.
    Rumor is that the overcoating of the film was changed. The
    original T-Max 100 and T-Max 400 were designed to have very
    similar development times so that they could be processed
    together. This is not true of the current films. The
    overcoating has an effect on the induction time, that is,
    the time between immersion the film in the developer and the
    first appearance of the image.
    In any case, the times for one stop pushing are the same
    as for normal processing.
     
    Richard Knoppow, Jul 16, 2006
    #4
  5. Steven Woody

    Steven Woody Guest

    many thanks to you. i think i was using F-32 for development of my
    T-MAX. it is amazing the those nagatives still show images :)
    actually, i've been using 12 mins in D-76 1:1, that should be 9 1/2
    instead.

    another question is, Kodak not list pushing time for D-76 1:1, how can
    i get know of it? i think, from EI100 to EI200, the time is no change
    for D-76, so do D-76 1:1 ( 9 1/2 mins ); from E1100 to EI400, the time
    changed to 8 1/4 mins which is 27% longer for D-76, so do D-76 1:1 ( 9
    1/2 * 1.27 = 12 mins ). am i right? thanks.

    -
    woody
     
    Steven Woody, Jul 16, 2006
    #5

  6. I use D-76 1:1 for T-Max routinely because I prefer the
    longer development times. I think for EI 200 I would follow
    the instructions for other developers, that is, no change
    from normal development. As a rule of thumb a one stop push
    requires about 1.5 times the "normal" time but I've seen
    Kodak instructions that suggest less. perhaps 30% increase.
    Beware that increasing development time does not really
    increase speed. It only increases contrast but the toe
    region of the characteristic curve, where the low exposure
    part of the image is, is also increased in contrast, which
    may make the images easier to print. The downside is that
    the contrast of the more normally exposed parts of the image
    will become very contrasty. Where you must push film the
    ideal lighting is pretty flat, however, one can not often
    choose in available light situations.
    Using a Phenidone developer will give you about 3/4 stop
    greater speed for the same contrast. They are better push
    developers than D-76. Among them are Kodak T-Max and T-Max
    RS, Xtol, Ilford Microphen, formula ID-68, and DDX, and a
    few others. With the exception of Xtol these all produce
    slightly coarser grain than D-76.
    Xtol is pretty close to being an optimum developer for
    many purposes but has proven to be somewhat unreliable.
    Ryuji Suzuki, a biological chemist, has done considerable
    research into developers and emulsions. Some of it is
    detailed on his web site at http://www.silvergrain.org. He
    has formulated a developer similar to Xtol but with some
    attention to curing Xtol's short time failure problem. It is
    now being put up commercially by Photographer's Formulary,
    details are on his web site.
     
    Richard Knoppow, Jul 17, 2006
    #6
  7. A correction: I am not sure if Ryuji Suzuki's film
    developer is available commercially yet. He has some paper
    developers which are. The formula for his film developer is
    on his web site. http://www.silvergrain.org You will have
    to do some poking around to find it.
     
    Richard Knoppow, Jul 17, 2006
    #7
  8. Steven Woody

    Steven Woody Guest

    thanks for your information!
     
    Steven Woody, Jul 17, 2006
    #8
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