Pushing and Pulling Film

Discussion in 'Photography' started by Cheryl Harms, Sep 27, 2005.

  1. Cheryl Harms

    Cheryl Harms Guest

    Ok, guys a couple of ground rules before the question: (1) No smart answers,
    just intelligent ones please. I'm too busy to wade through a bunch of junk
    that does not apply. (2)If someone does answer in a not so smart way, please
    forget about replying to what they said until the END of the discussion
    please.

    Please explain to me the concept of pushing and pulling film. My instructor
    has gone over a little about it, mostly on the pulling end of things, and
    what a few of the benefits of it are. I however am like a sponge at the
    moment and need more. I understand the idea of exposing film for the shadows
    and printing the paper for the highlights and that doing so will produce
    more shades of grey than the original 5 found in black and white film. I
    understand that when you pull the film to get these richer details you in
    the end produce a more pleasing photo. That is great for _pulling_ the film.

    What are the advantages of __pushing__ film? Would that be something that
    you would want to do primarily at night? If pulling basically overexposes
    film to a certain degree, then I must presume that pushing means that you
    underexpose your film. Why would someone want to purposely underexpose film?
    Please give me some intelligent feedback!
     
    Cheryl Harms, Sep 27, 2005
    #1
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  2. Cheryl Harms

    Sarge Guest

    Hi Cheryl,
    Pushing and pulling film is a technique that allows you to vary the ISO of
    color slide and B&W film, at the time of exposure, for practical and
    creative reasons.

    The most common technique is to 'push' film one or two stops by exposing it
    at a higher ISO setting than its actual film speed. (E.g., with 100 ISO film
    in the camera, set the ISO on 200 for a 'one-stop push' or on 400 for a
    'two-stop push'.) The camera meter is tricked into thinking that you're
    using faster film so that less light is required for correct exposure. The
    entire roll must be exposed at the new setting and the film lab must be
    informed so that the developing time is extended. If you don't inform the
    lab you'll end up with transparencies that are underexposed, or too dark. If
    you 'push' your standard films carry stickers or devise a foolproof method
    of identifying the film.

    Pushing film creates opportunities to take pictures in low levels of
    available light, instead of resorting to flash, using a tripod or having to
    hand-hold your camera at shutter speeds that risk camera shake.

    It also allows you to carry only one film stock and push the film as
    necessary in low light situations, rather than having to estimate in advance
    how much fast film you should carry on a trip.

    Be aware that when film is pushed, contrast and grain are both increased,
    which is why pushing film is not recommended in good lighting conditions.
    It's an ideal technique when working indoors and in low light. The increase
    in grain often adds to the mood of the shot.

    'Pulling film', rating film below its actual ISO, isn't a technique commonly
    used, but can be useful if film is accidentally exposed incorrectly. If you
    change from 400 ISO film to 100 ISO film but forget to change the setting on
    your camera, your pictures will be overexposed. Inform the lab and they'll
    compensate for the error in the processing.

    Rating film incorrectly has become less of a problem since DX coding, which
    reads the speed of the film and sets it automatically when it's loaded into
    the camera. DX coding has become a regular feature on modern cameras.

    Hope this helps

    Sarge.
     
    Sarge, Sep 27, 2005
    #2
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  3. Cheryl Harms

    UC Guest

    Who is your instructor? He should be shot for incompetence or for lying
    to you!

    Pushing does not work! All that it does is to change the contrast of
    the film, making the grain larger and causing highlights to bloom
    (blur).
     
    UC, Sep 27, 2005
    #3
  4. Cheryl Harms

    Rob Novak Guest

    You purposely underexpose to gain the advantages of higher shutter
    speeds in low light. You then "make up" for it in processing by
    overdeveloping the film, gaining grain and contrast on the way. For
    example, you'd process HP5+ in Ilford ID-11 for 7 1/2 minutes when
    shot at the rated speed of ISO400. Underexpose by a stop (shot at
    ISO800), and you develop for 10 1/2 minutes.

    In addition, some films exhibit desirable grain and contrast
    characteristics when pushed. Ilford HP5+ at 800 or Delta 400 at 1600
    are excellent examples - HP5's a low/medium contrast film at speed,
    but shooting it with a one-stop push gives higher contrast at the
    expense of a little bit of grey tonality. Delta 400 at speed has
    good contrast and tonality, and has a relatively fine grain for its
    speed. Pushing it two stops, however, gets you a bit more contrast
    with very little loss of shadow detail, and brings out a sugary,
    velvety grain that is desirable for certain moods.
     
    Rob Novak, Sep 27, 2005
    #4
  5. Cheryl Harms

    Cheryl Harms Guest

    UC,
    The only thing he has explained about is pulling the film not __pushing__
    it. I had explained that and you will see that I had if you just go back and
    read it over again. I am one of those people who is not very content to go
    at the snail's pace required of many classroom situations and that is why I
    came to this group for a reasoned and logical discussion ahead of time.

    As for your assertion that it categorically does not work and that my
    instructor should -from your point of view- be shot for lying...well give me
    proof to your facts and then I MIGHT consider finding my local peashooter
    marksman and putting a contract out on the one teacher I've had so far that
    has taught me what little I didn't already know. (All said tongue in cheek
    because this guy is better than the one I had for my basic class that just
    glossed over any important and need information!!!)

    I'm here to learn and if you can't or don't want to teach, please save your
    replies for the end of the thread when I have become bored with bias-laden
    remarks. **I** don't have time for that garbage even if you do!!
     
    Cheryl Harms, Sep 27, 2005
    #5
  6. Cheryl Harms

    UC Guest

    Cheryl:

    Look at any H&D curve.

    http://www.kodak.com/global/en/professional/support/techPubs/f9/f002_0361ac.gif

    http://www.kodak.com/global/en/professional/support/techPubs/f9/f002_0357ac.gif

    http://www.kodak.com/global/en/professional/support/techPubs/f9/f002_0355ac.gif

    Look at the 'speed point' and see how much it moves with changes in
    development time (it hardly moves at all). The 'speed point' is just to
    the right of where the curve starts going upward. Changes in
    development time DO NOT yield more speed at all, just more contrast.
     
    UC, Sep 27, 2005
    #6
  7. Cheryl Harms

    Rob Novak Guest

    I see you've met our main troll. Please don't feed it.
     
    Rob Novak, Sep 27, 2005
    #7
  8. Cheryl Harms

    McLeod Guest

    Please put UC in your killfile, like everyone else on usenet has.
     
    McLeod, Sep 27, 2005
    #8
  9. Cheryl Harms

    Dirty Harry Guest

    amen
     
    Dirty Harry, Sep 27, 2005
    #9
  10. Cheryl Harms

    Cheryl Harms Guest

    Even Randall drops more crumbs of info than this "UC" person has so far.
    Therefore he (UC) has been blocked and will hereafter be IGNORED!!
     
    Cheryl Harms, Sep 27, 2005
    #10
  11. Cheryl Harms

    Mark W. Oots Guest

    Ok, I've read all the replies so far (except UC's, which were blocked).
    Simple version of pushing or pulling is exactly what you think, over or
    under exposure (usually by 1 stop). With most black and white, silver based
    films, developing is modified to produce the expected results (under expose
    & over develop and vice versa). However, over or under exposure is not
    exactly what you are doing. You can actually decide ahead of time what the
    lightest and darkest areas of the print will be that include detail.
    Processing is adjusted to maintain that detail and the "gamma" or contrast
    ratio of the film is changed to allow it to record what you want. This is
    impossible with roll films, at least by individual frames, so you simply
    "push" or "pull" the whole roll. For a high contrast scene, "pull' one stop
    (to reduce the max/min contrast ratio) and in low contrast (usually low
    light) conditions, "push" one stop to increase the contrast ratio.Remember,
    processing must be modified to get the results you are looking for. With
    sheet films, you decide what values will be the darkest that hold detail
    (everything below that is black) and the lightest areas with detail
    (everything brighter will be paper white). Recording the detail on the
    negative is the first step.

    When I shot pix for the school paper (when dinosaurs roamed the earth), we
    pushed TriX to 1600 for basketball and football games all the time, but the
    contrast was really high, nearly litho type ratios. We also used litho and
    copy films (gamma of nearly 1:1) as continuous tone films by "pulling" them
    a dozen or more stops and using specific processing to get extremely fine
    grain and near sheet film details out of 35mm.

    A little light (pun intended) reading...Ansel Adams'..(anything he ever
    wrote) "The Negative" & "The Print" as well as any reference to the "Zone
    System" you can find. When Adams died, everyone who ever took a snapshot
    moved up one spot in the rankings.

    Yes, I do have digital (though only been working with it for a couple
    months) and yes I do still shoot film (35mm, 6X6cm and 4X5 inch).

    And for UC, who though I won't see his reply, since I've blocked everything
    from him,...I do NOT own a 'Blad, though I recently did sell my RB67 and 645
    bodies and lenses because I could no longer justify having them AND 4X5,
    because I just get so much better quality from true large format. I do still
    shoot medium format, but not much.

    Sorry so long winded. Just my 2 cents.
    Mark
     
    Mark W. Oots, Sep 27, 2005
    #11
  12. Cheryl Harms

    Diverse Art Guest

    Cheryl,

    What you've described there is *not* 'pulling' the film. It's just a
    standard exposure technique. What you've missed out in your description is
    the processing of the film itself.

    Basically, when you 'pull' a film, you expose it as it the ISO rating, the
    film speed, is slower than the normal rating (remembering that ISO ratings
    are only guidelines, they are not written in stone). For example, if your
    film is normally rated at ISO 100, then to 'pull' it by one stop you would
    expose the shot as if the film were ISO 50 (ie, give it an extra stop's
    worth of exposure) and then compensate for this extra exposure by giving it
    less development.

    'Pushing' a film is the exact opposite. Pushing the same film by one stop
    means giving it one stop *less* exposure, as if it were ISO 200 and
    compensating by giving the film more development.

    Personally, I have never pulled a film - never found a convincing reason to
    do so. I guess one reason you might do this is because you actually want
    long exposure times for deliberate blurring or whatever. Another reason is
    to adjust contrast etc - ie, it becomes a personal decision about the kind
    of negative you want.

    Pushing film allows you to shoot under lower light conditions because you're
    treating the film as though it were faster. The additional grain and
    contrast that result can produce a nicely 'gritty' effect, too.

    Bear in mind that you push or pull an entire film - not individual shots -
    because the process involves the development stage.

    Note - this is *not* the same as simply shooting at a different ISO setting
    from the recommended. For instance, I shoot most ISO 400 negative films
    with the meter/camera set to 320. This gives a little extra exposure by
    default, but I stick to standard development, so this is closer to the
    'exposing for the shadows' technique you outlined which, by itself, is
    *not* 'pulling'.

    Some films are less tolerant of this treatment than others. Kodachrome, for
    instance, hates it.
     
    Diverse Art, Sep 28, 2005
    #12
  13. Cheryl Harms

    Rhys Sage Guest

    WHen I used film (I'm 99% digital now), I pulled and pushed film. I
    once pulled a 400ASA slide film down to 100ASA and was mightily
    impressed by the increase in colour contrast. I once pushed a 3200ASA
    colour print film by 3 stops just to get extra shutter speed. It worked
    although the colour went to hell.

    I got the pictures but the colour wasn't very interesting. With black
    and white film, it's easier - you just get higher shutter speeds at the
    expense of higher grain. It's handy if you need 400ASA film but you
    only have 100ASA.
     
    Rhys Sage, Sep 28, 2005
    #13
  14. Cheryl Harms

    Cheryl Harms Guest

    Thank you for all the info. Diverse Art is correct in saying that I only
    described part of the process and that I left out the adjustments needed in
    processing the film. What I was mostly going for was information as to the
    situations where the exposure + development deviation could possibly be
    useful. Other than for class purposes, I plan to use my materials wisely
    since as a mother and grandmother of two who is also a student buying a
    truckload of medication and supplies for school every month I have very
    little to spend on things that are not practical to making a living somehow.
    I am however of the belief that the more you are informed about something,
    the better a person will be able to choose what is best for him or her.

    Having said that, now is the time for you guys to show your *stuff* if there
    is anything smart-alecky wise you want to say. I am now off my serious time
    soapbox. :)
     
    Cheryl Harms, Sep 28, 2005
    #14
  15. You need to run film tests to determine the film speed for the way you
    shoot/develop. It's way more involved than I want to type at the
    moment.

    Once you've determined your personal ASA for whatever film, you can
    develop longer or shorter depending on the contrast range of the scenes
    you photograph.

    For example, around this part of the country, it's overcast a lot.
    Therefore the contrast is quite low. To compensate for that, one would
    develop the film a little longer based on your film tests (push) to get
    normal contrast. In high contrast situations, you'd develop for less
    time (pull) to get normal contrast and the full tonal range.
     
    Randall Ainsworth, Sep 28, 2005
    #15
  16. Tell that to Ansel.
     
    Randall Ainsworth, Sep 28, 2005
    #16
  17. Read my post...I explained it in polite terms. It was an intelligent
    question for a change.
     
    Randall Ainsworth, Sep 28, 2005
    #17
  18. Using the Zone System properly requires consistent development
    techniques and doesn't really lend itself well to roll film.
     
    Randall Ainsworth, Sep 28, 2005
    #18
  19. Cheryl Harms

    DBLEXPOSURE Guest





    Great thread!

    I only have had to do this once. I hesitate to bring it up, I understand
    how you feel about football :) Anyway, I went to the season opener last
    year at the Metrodome. I was using a 75-300mm f/4-5.6 (A lens I am not fond
    of) Anyway, in order to hand hold at 300mm with this slug of a lens I had
    to underexpose two stops. When I got home I looked up on-line the timing
    charts for the chemistry I use. I pushed the developing time two stops and
    the results where okay, not great, but Okay. I wish I could tell you what
    film I was using, As Randall had mentioned, it does make a difference in the
    results, but I am in the process of moving and all my negs are packed away.
     
    DBLEXPOSURE, Sep 28, 2005
    #19
  20. Cheryl Harms

    Stan de SD Guest

    Usually a stop or two of overexposure isn't a problem for negative film.
    "Pulling" film is done primarily for contrast control and a slight
    improvement in grain when done in B&W processing with mild or dilute
    developers. Back in the pre-digital days, some commercial photographers used
    to pull E-6 film about 2/3 of a stop when shooting for reproduction purposes
    as opposed to shooting projection tranparencies. The lower contrast avoided
    the need to make a mask, especially when working with high-contrast printing
    methods such as Cibachrome...
     
    Stan de SD, Sep 28, 2005
    #20
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