Are All B&W Films Balanced for Tungsten?

Discussion in 'Darkroom Developing and Printing' started by Dan Quinn, Sep 7, 2003.

  1. Dan Quinn

    Dan Quinn Guest

    Noting the spectral sensitivity of several Ilford films I saw that the
    graphs were generated using tungsten light. The graphs show a generally
    flat response from deep blue through deep red. Is that the case with all
    B&W films? Dan
     
    Dan Quinn, Sep 7, 2003
    #1
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  2. Dan Quinn

    Mark A Guest

    Except for infrared films, that is true to best of knowledge.
     
    Mark A, Sep 7, 2003
    #2
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  3. Kodak Technical Pan has extended red sensitivity.
     
    Michael A. Covington, Sep 8, 2003
    #3
  4. I very much doubt it. In my older books, they give two film speeds, one
    for daylight, and a lower one for tungsten illumination (which was
    lower). Guess what speed they put on the box?

    But what does "balanced for color" mean when dealing with black and
    white films? They sometimes give spectral response of film with respect
    to some light source or other and you can look at the curve if you like.

    Let us look at some Kodak films:

    Commercial Film 4127
    Speed: White-Flame Arc: 20
    Daylight: 50
    Tungsten and Quartz Iodine: 8

    Contrast Process Ortho 4154
    Speed: White-Flame Arc: 100
    Tungsten and Quartz Iodine: 50
    Pulsed-Xenon Arc: 100

    Contrast Process Pan 4155
    Speed: White-Flame Arc: 100
    Tungsten and Quartz Iodine: 80
    Pulsed-Xenon Arc: 100

    Ektapan 4162
    Speed: ISO 100/21

    High Speed Infrared 4143
    Speed: Exact speed numbers cannot be given
    for infrared film because the ratio
    of infrared radiation to light is
    variable...

    Kodalith Ortho Film 2556, Type 3
    Speed: White-Flame Arc, Kodalith Developer 12
    Tungsten, Kodalith Developer 8; D-11 25

    Tri-X Ortho 4163
    Speed: Daylight: ISO 320/26
    TungstenL ISO 200/24

    Enough, right?
     
    Jean-David Beyer, Sep 8, 2003
    #4
  5. All B&W films have their greatest sensitivity to violet and blue
    light, and any graph made with 'equal energy' source (daylight) will
    show that. Silver halide crystals in their raw state are sensitive to
    violet and blue light only. It's not possible to match this basic
    sensitivity of the silver crystals to violet and blue light with
    sensitizers, which extend the sensitivity to other wavelengths. In
    other words, the green, yellow, red, and infrared will always be
    recorded less intensely.
     
    Michael Scarpitti, Sep 8, 2003
    #5
  6. One of the Ilford films does too (sorry I don't remember which). EFKE KB25
    and the Maco (Mako?) films are orthopanchromatic. They have less red
    sensativity.

    Geoff.
     
    Geoffrey S. Mendelson, Sep 8, 2003
    #6
  7. Dan Quinn

    Dan Quinn Guest

    The higher. I checked Ilford; 2850K.
    This thread has to do with some filter selections. I've noted while
    looking through B+W's catalog that any of the usuall yellow through
    red filters used for B&W entirely eliminate the blue end of the
    spectrum. Moveing toward red progresively obliterates the
    shorter wavelengths.
    I think I'll try the filters used with color film. They do pass the
    entire spectrum. The blues, cyans, and greens of the Deep Dark Forest
    must register. Dan
     
    Dan Quinn, Sep 8, 2003
    #7


  8. Your answwer makes no sense. What are you trying to accomplish? B&W
    film's highest sensitivity is to violet/blue light, lowest is to
    green. The graph you should be using to look at the film's response to
    daylight is the daylight curve, if you're working in daylight. If you
    want a more 'natural' tonal representation of colors,c closer to the
    brightness values as they appear to the eye, use a yellow-green
    filter. The filters used for color film will be of no value
    whatsoever.

    See: http://www.schneideroptics.com/filters/filters_for_still_photography/black_&_white/

    "B+W 060 yellow-green [11]
    This filter is ideal for scenes where it is important to differentiate
    the green tonal values. The application is especially suited to
    landscape photography in the springtime because it enhances the light
    green color of the leaves. Due to its favorable effect on red tones,
    this filter is also suitable for portraits or group pictures taken in
    natural light. Filter factor is approx. 2."
     
    Michael Scarpitti, Sep 8, 2003
    #8
  9. Ilford's SFX is supposed to have extended red sensitivity. But IMO Tech Pan's
    extra red is more dramatic.
     
    steven.sawyer, Sep 8, 2003
    #9
  10. I have seen skylight filters designed for B&W film. I don't own one so I don't know if their just wasted
    glass or not.

     
    steven.sawyer, Sep 8, 2003
    #10
  11. Dan Quinn

    Dan Quinn Guest

    RE: (Michael Scarpitti) wrote
    Just try and find some.
    Consulting my B+W cataloge I see that the 060 reaches 60%
    transmission at 500nm, a peak of 82% at 550nm, then dips to 60%
    at 660nm.
    I'll likely add a KR 12 to my B+W collection. According to B+W
    the KR 12 is to be used when TUNGSTEN BALANCED color film is
    used outdoors.
    As far as I know color films use panchromatic emulsions with color
    couplers. So where do tungsten balanced B&W and color films differ
    in so far as response to filtration? For good color fidelity,
    filters for color film pass an entire spectrum of colors. Dan
     
    Dan Quinn, Sep 8, 2003
    #11


  12. You're shooting in daylight, right? B&W film is most sensitive to
    violet and blue, right? Daylight has more blue than yellow or red,
    right? That means there's too much blue recording on B&W film, right?
    You need a yellow-green filter. Period.
     
    Michael Scarpitti, Sep 9, 2003
    #12
  13. Dan Quinn

    J Stafford Guest

    No no! Those are mere Contrast filters. You use a yellow-green filter
    _over_ color correcting filters. Yeah, that's the ticket. I know because
    my wife, ah, Morgan Fairchild, yea that's it, she told me.

    But seriously, B&W photography _is_ color, and color correction is a fine
    part of the craft. Contrast filters suffice, but if the man want's to
    learn CC and use them, so be it. Maybe he will have some refined outcomes,
    but Contrast filters have the more dramatic changes that people tend to
    want.
     
    J Stafford, Sep 9, 2003
    #13
  14. Dan Quinn

    Norman Worth Guest

    All black and white films can be used with tungsten light, but (as noted in
    some other replies) the speed may be different than the speed for daylight,
    depending on just how it is sensitized. The filter factors (if you use
    filters) may also be different. The manufacturer's data sheet usually gives
    the details you need to know. It can usually be found on the manufacturer's
    web site if it doesn't come packed with the film.
     
    Norman Worth, Sep 9, 2003
    #14
  15. In the 19th century, B&W film was most sensitive to near ultra-violet
    and blue. But with the sensitizing dies due to Vogel and Ives and later
    many others, film has been sensitized to longer wavelengths all the way
    into the infra-red. Some film now has more sensitivity in red than in
    blue I understand.
     
    Jean-David Beyer, Sep 9, 2003
    #15
  16. Dan Quinn

    mr. chip Guest

    Funny you should say that. I was just reading about the sensitivity of the
    newer T-Max films and apparently they have a reduced sensitivity to the blue
    end of the spectrum, as well as the red. The article states that this is
    part of a trend to produce images which correspond more accurately to what
    the eye sees.

    Simon.
     
    mr. chip, Sep 9, 2003
    #16


  17. Previous to T-max films, green sensitivity was poor.
     
    Michael Scarpitti, Sep 9, 2003
    #17
  18. Dan Quinn

    Dan Quinn Guest

    RE: (Michael Scarpitti) wrote
    Perhaps that is the reason graphs show only a balance to tungsten.
    Tungsten being weak in short wavelenghs makes it possible for manufacturers
    to make a film with a balance to the tungsten spectrum. Dan
     
    Dan Quinn, Sep 10, 2003
    #18
  19. Hi Dan,

    Looking at Kodak spectral sensitivity data:

    1. Plus-X
    http://www.kodak.com/global/en/professional/support/techPubs/f4018/f009_0431ac.gif
    Peak (log 1.9 at 400 nm dropping to log 1.1 at 520 nm rising a little
    before dropping to log 0.5 at 650 nm

    2. Tri-X
    http://www.kodak.com/global/en/professional/support/techPubs/f4017/f009_0506ac.gif
    Steady between log 2.6 and log 2.2 from 300 nm to 630 nm

    3. T-Max 100
    http://www.kodak.com/global/en/professional/support/techPubs/f4016/f002_0547ac.gif
    Relatively steady between log 1.5 and log 1.0 from 400 nm to 630 nm

    4 . T-Max 400
    http://www.kodak.com/global/en/professional/support/techPubs/f4016/f002_0511ac.gif
    Declining slowly from log 2.0 to log 1.5 between 410 nm and 640 nm

    5. T-Max 3200
    http://www.kodak.com/global/en/professional/support/techPubs/f4016/f002_0523ac.gif
    Declining slowly from log 2.2 to log 1.5 between 420 nm and 650 nm

    6. Tech Pan
    http://www.kodak.com/global/en/professional/support/techPubs/p255/f002_0194ac.gif
    slightly U-shaped from log 1.2 to log 0.5 to log 1.8 and again to log
    1.5 at 310, 500, 650 and 680 nm respectively

    So I would conclude that, in general, Kodak films are more sensitive to
    blue green light [fluorescent] than to yellow-orange light [tungsten].
    Tech Pan is ok. The slower T-Max films are not as good, but 400
    outperforms 100, as a fall off of log 0.5 from 1.5 to 1.0 is actually
    fairly significant. Plus-X droops badly, but Tri-X is at least fairly
    level.


    Francis A. Miniter
     
    Francis A. Miniter, Sep 10, 2003
    #19
  20. Francis:

    These Kodak curves appear to be made with daylight, not 2850K.
    Therefore, they show the inherent greater sensitivity to blue light
    and depressed green sensitivity. Kodak and Ilford's conventional films
    are not that different. The T-grain and delta films are also fairly
    similar in spectral response.

    The same energy source would give similar results with Ilford films.
     
    Michael Scarpitti, Sep 10, 2003
    #20
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