Pulling film - what the heck?

Discussion in 'Black and White' started by kevin_bourque, Oct 21, 2006.

  1. Hi All -

    A frequent question here goes something like this, "I accidentally exposed TMAX
    400 at 200 and I want to know the right development time to pull it".

    First, no knock on the guys that asked the question. It's not unreasonable.
    But it exposes an underlying fallacy, namely that exposing a film at a speed
    less than whats on the box is an error, and needs to be fixed.

    First, the whole notion of film speed is kind of loose to begin with. TMAX 400,
    HP5 and Tri-X all say 400 on the box, but they are NOT the same speed.

    Second, WHAT you're shooting makes a difference. On a flat day with no shadows,
    you could probably expose Tri-X at 800 without too much trouble. If you have a
    black cat in the coal bin next to a white sheet in full sunlight, you might have
    to be more careful!

    Third, if you use the "speed point" definition for exposure index (Zone I = film
    base + 0.1), most films are best exposed at about one stop less than what's on
    the box. For instance, when I use a spot meter, I usually place the darkest
    thing I care about on Zone III. In full sunlight this setting is frequently
    equal to a one-stop overexposure. That is, I'll exposure Tri-X at f16 at 1/250.
    The exceptions usually lean to even more exposure. If averaging meters get
    fooled, it's usually in the direction of underexposure.

    Last (and most important), most modern B&W emulsions have a very large tolerance
    for overexposure. I think color neg films do, too. Slides are a different
    animal altogether. Older emulsions used to run out of headroom a lot more
    quickly, and you had to pay attention to fitting the brightness of the scene to
    the range of the film (via expanding and contracting).

    I'll let someone else talk about ISO and EI being different things, and the
    effects of various developers.

    The bad thing about underdevelopment (pulling) is that you've decreased the
    overall contrast of the scene. It might look fine....but you may well end up
    printing with a higher contrast paper or filter, effectively putting back what
    you took away.

    Try this....get a roll of your favorite 400 speed film. Set the camera on 100,
    walk outside on a nice bright day and shoot the roll. Whoa, a two-stop
    overexposure! Surely I'll get in trouble for this! Process as normal (no
    pulling!). Make some prints, and let us know how they look. I'm not advocating
    shooting Tri-X at 100, but it will set you mind at ease when it comes to need to
    "pull". The camera will not self-destruct, I promise.

    Of course, you may end up with a greater brightness range than your paper can
    handle, but that's where burning, dodging and paper grades come into play. Or,
    you can just print the shadows to black. Better to have it on the negative,
    though!

    Good light!
     
  2. Somewhere in the archives is a set of color photos under a topic with the word "armchair" in the title and started by James Dainis. It goes through this whole argument and illustrates it with a series of photos. I posed a whole set myself there or under another thread.

    Ron Mowrey
     
  3. I pretty routinely shoot at 1/2 speed and cut development 20 %. The pics seem to have less internal contrast, but the end points are the same.

    Try some and see as it is hard to describe. You will like the finer grain and easier printing too. No they do not come out looking flat and lacking contrast.
     
  4. I have read that cutting development reduces contrast even in the midtones, where full-bodied contrast is desirable, but that using a 2-bath compensating developer (such as AB-55) will maintain contrast in the midtones while reining in contrast in the highlights, thus rendering them more easily printable.

    My limited experience with different developers seems to bear this out, though my experience is neither so extensive nor systematic as to be reliable proof of anything.

    Generous exposure to open up the shadows a bit coupled with compensating (as opposed to reduced) development to maintain midtone contrast and reduce highlight contrast would seem to be one way to produce easily printable negatives with optimal tonality.

    Some 2-bath compensating developers, such as AB-55, have the added advantage of being relatively insensitive to variations in development time and temperature.

    Am I headed down the right track, or is this approach another magic bullet that has been tested and found wanting?
     
  5. Two-bath developers are fine, Jonathan. I use 'em myself. They're not a magic bullet at all (at least in the "one thing that's going to make my pictures great" sense).

    Similarly, if anyone chooses to develop film for less then what the manufacturer recommends, that's their choice (especially if they're happy with their pictures). I generally fall into that camp, too.

    Just to restate my point, there's seems to be a notion out there that if you overexpose your film a little (a stop or two), it needs rescuing. In my experience, it does not. All the rest of the rant was to explain why I would say such a thing. All are free to disagree, of course.
     
  6. Kevin, your point is well taken, but there is a point of no return, when one starts getting bulletproof negatives, so dense in the highlights that they can't be printed through. The time-honored rule, as good today as it was 40 years ago, is "expose for the shadows, develop for the highlights." Developing for the highlights can mean reducing the developing time.
     
  7. It might be worth adding that if you want the lowest graininess with silver-image negative film, then it is best to give the minimum satisfactory exposure.

    Best, Helen
     
  8. I rarely shoot film at rated speed. Even at the merest hint of brightness I downrate, in bright light by as much as one and one-third stops, e.g. 100 ASA film at 40 ASA. That way in a landscape shot I can print highlight detail in clouds without ythe need to drop to a lower grade or burn in.
     
  9. "But it exposes an underlying fallacy, namely that exposing a film at a speed less than whats on the box is an error, and needs to be fixed. . . . Of course, you may end up with a greater brightness range than your paper can handle, but that's where burning, dodging and paper grades come into play."

    For many folks, those two statements are not compatible. While I appreciate that one can accomplish alot with darkroom controls, due to skill level or equipment choice, these controls aren't available to everyone. In my case, since I'm scanning, a density too high for the scanner's light to penetrate just means lost data. Even normal development often results in highlights too dense to scan, so a two stop overexposure would be a disaster.
     
  10. "Second, WHAT you're shooting makes a difference. On a flat day with no shadows, you could probably expose Tri-X at 800 without too much trouble. If you have a black cat in the coal bin next to a white sheet in full sunlight, you might have to be more careful!"

    Acually, according to my experience, there should be no difference in EV on a day with flat light and full sunshine if you take an incident meter reading in the shadow in both cases and expose the film accoeding to that. Of course, development would have to be different. The reason why most people rate their film lower in contrasty than in flat lighting is because they use a light meter that probably takes an average reflected reading, hence the shadows will be well below the average on a sunny day, while not that far from the average on an overcast day.

    Try an incident meter, and you'll see what I mean. Actually I think an incident meter is a better tool for black and white photography than a spot meter (at least for 35mm and MF film, I don't know anything about working with sheet film).
     
  11. Example 1
    00IWfJ-33096984.jpg
     
  12. I've found the few times I've pulled a stop and cut development the negs were grainier and the shift in tonality just wasn't too my likeing. The image below was taken on Pan F+ rated at 50, the box speed. I took an incident reading in front of the mans face and simply exposed at the meters suggestion. I got enough shadow detail to serve the print (at least for me, others here may have taken a different approach) and the light coming through the window while blown out probably would have stayed that way even with a one stop pull. I'm sure the contrast range between that and the shadows was more then the films latitude.
    00IX5O-33107884.jpg
     
  13. I worked with D23 two bath for a few years ( old Leica formula ) and it worked well except I lost a lot of highlight separation. It was not obvious at first, but as I got more experience, I could see the difference.
     
  14. I pretty routinely shoot at 1/2 speed and cut development 20 %. The pics seem to have less internal contrast, but the end points are the same.
    Try some and see as it is hard to describe. You will like the finer grain and easier printing too. No they do not come out looking flat and lacking contrast.
    Around 1959 or 1960, pretty much all B&W films doubled in speed overnight. There was no change made to the emulsions. The ASA (and/or "the industry") merely reevaluated the "safety factor" built in to the then-current film speeds, and determined that they could safely trim one stop off the speeds without losing too much "safety".
    Many people prefer to use the pre-revision speeds, and give a tad less development. The result is a much richer tonality, with smoother gradation, at times approaching that of a next-size-larger format. (The larger the negative, the smoother the gradation.)
     
  15. Nice! I was just reading through threads, I don't know what prompted this topic but I'm
    glad you, Kevin, wrote something about this. It's always nice to read someone encouraging
    folks to experiment with photography. It's one of the best ways to learn how film reacts to
    light and development and everything else.
    <p>
    >>First, no knock on the guys that asked the question. It's not unreasonable. But it
    >>exposes an underlying fallacy, namely that exposing a film at a speed less than whats
    >>on the box is an error, and needs to be fixed.
    <p>
    I don't know about anyone else, but making "errors" teaches me better than when I get
    things right.
     
  16. I think Kevin's point is one about modern film's overexposure latitude, and it's one that bears repeating, so I thank you, Kevin. Regarding optimum exposure and development, there remains some differences of opinion.

    The old adage, "expose for the shadows, develop for the highlights", might resonably be restated as "expose for the highlight development". The statement in its original form seems to treat the exposure and development as separate entities, but in fact, they are inextricably linked, and development determines exposure. In a very low contrast scene with a brightness range of a stop or so, there are no discernable shadows, or highlights, so if we follow the old adage, how do we procede? If we want the scene to print with good separation of values, we must increase development, and reduce exposure accordingly. In the instance of a very high contrast scene, development must be reduced to maintain printable highlight densities, and as a result, exposure must be increased so that the shadow values will be adequately developed within the reduced development time. In all cases, the negative must be scaled to the printing paper. VC papers offer a continuous range of contrast, unlike the stepped grades of graded papers, but local contrast changes with paper contrast, whether graded or VC, so the exposure scale of the paper should be chosen carefully, and the negative scaled to it.

    Back to Kevin's point. If we use for our example an average scene, and assume an accidental overexposure of 2 stops, what do we gain by reducing development? Since the shadows are 2 stops more dense than normal, normal development will result in reduced contrast, and reduced development will only exacerbate the problem. Some of the contrast can be recovered by chosing a harder paper, but local contrast could be harsh, especially for a portrait. More than normal development will restore some of the lost contrast, but at the expense of added density and the grain that comes with it. In my own opinion, the best course is to recover as much contrast as possible through a combination of normal development and a harder paper, instead of relying on one or the other to do all of the recovery work, and utilizing all of one's printing skills to extract the best possible print from a less than optimum negative.

    Jay
     
  17. Don't want to make things more complicated but according to their latest (2003) technical brochure Ilford engineers do NOT recommend pullling their films more than 2/3 of a stop.
    EXAMPLE : for a 400 Iso film they recommend exposing it at 200 Iso at the lowest.
    400 Iso (Delta or HP5) films that have been exposed at 50 100 or 160 Iso are to be processed in undiluted Perceptol. Any other developer (ID11 or others) are in this case NOT recommended.
    Any opinion from "Silver Star" photographers? :)
    Thanks!
     

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