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  1. #11
    David Allen's Avatar
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    Hi there,

    no one here will be able to give you a comprehensive answer because we can't see the negatives and there are so many possible variables to consider such as how you meter a scene, etc. Also, if a scene has a lot of highlights and mid-tones the negative will look far denser than a negative with a wider spread of tones. The rule of thumb 'Expose for the shadows and develop for the highlights' is good advice but only when you know the true spped of the film with your equipment and also HOW to expose for the shadows and HOW to develop for the highlights.

    If you want to save yourself a lot of time, film and frustration, the best idea would be to put aside an afternoon to carry out some tests that will, once and for all, determine the correct Exposure Index for a particular film in your equipment, with your way of processing, your enlarger, etc. When undertaking the tests it is important to use direct metering (metering directly from part of the scene) so you know exactly what you are metering rather than the vague averaging that an incident dome or averaging meter in the camera will give you.

    The real key to testing a film/developer combination is to use a consistent and repeatable system. For your information, the following is the testing system that I have taught for many years. It is not the only way to approach testing or exposure BUT it is a system that reliably puts photographers (even novices) quickly in control of their exposure/development regime. It does not require densitometers but rather relies on doing things in a practical manner and relies on using your own eyes to achieve results that suit you.

    So on to the testing regime. The key to achieving consistently good negatives is the correct placement of your shadows when exposing the film and ascertaining the correct development time for achieving good separation without losing the highlights. A simple and relatively quick way to way to pin all this down for the future is to do the following (WARNING: reading these instructions is more time consuming and a lot more laborious than actually doing it!!):

    1. Find a scene with with a good range of tones
    2. Using the box speed, meter the darkest area in which you wish to retain shadow detail
    3. Move the camera so that you are only photographing this shadow area
    4. From the meter's reading close down the aperture by 2 stops or increase the shutter speed by two stops and then expose 6 frames at: the given exposure then +1 stop, +2 stops, -1 stop, -2 stops and -3 stops less than the meter has indicated

    5. Process the film

    6. Using the frame that was exposed at -3 stops less than the meter indicated (which should be practically clear but will have received lens flair and fogging - i.e a real world maximum black rather than an exposed piece of film that has processing fog) and do a test strip to find out what is the minimum exposure to achieve maximum black - Print must be fully dry before assessing this
    7. Do another test strip with the first exposure being what you have selected for achieving maximum black minus your dry-down compensation then plus 1 second, 2 seconds, etc (this is to double check that you have indeed found the correct minimum exposure for maximum black - i.e if your first maximum black time plus an extra 2 seconds give you a darker/deeper black then this is the correct time to use).
    8. The time that achieves full black inclusive of compensation for dry-down is you minimum exposure to achieve maximum black for all future printing sessions - print must be fully dry before assessing
    9 You now know the minimum time to achieve full black inclusive of exposure reduction to accommodate dry-down
    10. Using this minimum exposure to achieve maximum black exposure time, expose all of the other test frames.
    11. The test print that has good shadow detail indicates which exposure will render good shadow detail and achieve maximum black and provides you with your personal EI for the tested film/developer combination

    12 If the negative exposed at the meter reading gives good shadows, your EI is (when metering shadows where you wish to retain good detail) the box speed (i.e. for 400 film you need to set your meter at 400)
    13. If the negative exposed at +1 stop more than the meter reading gives good shadows, your EI is (when metering shadows where you wish to retain good detail) 1/2 the box speed (i.e. for 400 film you need to set your meter at 200)
    14. If the negative exposed at +2 stops more than the meter reading gives good shadows, you EI is (when metering shadows where you wish to retain good detail) 1/4 box speed (i.e. for 400 film you need to set your meter at 100)
    15. If the negative exposed at -1 stop less than the meter reading gives good shadows, you EI is (when metering shadows where you wish to retain good detail) double the box speed (i.e. for 400 film you need to set your meter at 800)
    16. If the negative exposed at -2 stop less than the meter reading gives good shadows, you EI is (when metering shadows where you wish to retain good detail) 4x the box speed (i.e. for 400 film you need to set your meter at 1600)

    You have now fixed your personal EI but there is one more testing stage to go.

    1. Find a scene with with a good range of tones
    2. Using your EI, meter the brightest area in which you wish to retain highlight detail
    3. Move the camera so that you are only photographing this highlight area
    4. From the meter's reading open up the aperture by 3 stops or decrease the shutter speed by three stops
    5. Expose the whole roll at this setting
    6. In the darkroom, process one third of the film for recommended development time

    7. When dry put negative in the enlarger and make a three section test strip exposing for half the minimum black time established earlier, for the established minimum black time and for double the minimum black time.
    8. Process print and dry it.
    9. If the section of the test strip exposed for 1/2 the minimum black time gives bright highlights with a trace of detail then the film requires 20% more development
    10. If the section of the test strip exposed for the minimum black time gives bright highlights with a trace of detail then the film is correctly developed
    11. If the section of the test strip exposed for double the minimum black time gives bright highlights with a trace of detail then the film requires 20% less development
    12. You can use the rest of the exposed highlight test film to fine tune the development time.

    YES - it is VERY boring but . . .for the investment of minimal materials and a few of hours you will have pinned down so many variables that it is really worth doing.

    Back in the real world, all you need to do in future is meter the shadows that you wish to retain good detail with meter set at your EI and then stop down the aperture 2 stops or increase the shutter speed by 2 stops. In the darkroom start your first test print with the minimum exposure to achieve maximum black (inclusive of dry-down compensation) and go from there.

    Best,

    David
    www.dsallen.de

  2. #12
    markbarendt's Avatar
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    Quote Originally Posted by mporter012 View Post
    Hello -

    I've read quite a bit about the benefits of ''exposing for the shadows, developing for the highlights.'' Last year, I was shooting tri-x 400 at 200 and developing normally and ending up with negatives that were REALLY dense. Here's what I've been working with now: Tri-x 400. Fm2n. I've been cutting the film speed in half and shooting at iso 200, and then cutting the development speed in half by 20%. Our darkroom water is pretty consistently 68 degrees, so according to kodak, I should be developing d76 at 9+3/4 minutes. So cutting that by 20% leaves me at 7:45s or so. My negatives are coming out pretty thin, which makes me think I'm under developing. Can anyone give me some advice?

    Thanks -
    Four thoughts:

    First, and yes it is the boring way, following Kodak's instructions for shooting and developing at box speed is a great way to get a good baseline to work from. This also makes trouble shooting problems easier and if you do a good job of following Kodak's instructions for normal, the film will get exposed and developed in a way that will provide good prints in most situations.

    Second, IMO adjusting away from box speed and normal development should typically only be considered if "normal" isn't working for you. Exposing TriX for 200 is a good idea if you are getting poor shadow detail in your prints when you shoot at 400. If you normally got plenty of shadow detail at 400, just shoot at 400.

    Third, and again IMO, adjusting your developing process away from normal, + or -, should only be done to solve real print contrast problems or to refine "your" normal. The look of your negative is largely irrelevant; the positive, the print is what matters. And if you are using variable grade papers, or some other adjustable printing method, adjusting your film development away from "normal", especially with roll films where a variety of settings may have been photographed, is also largely irrelevant and can actually make your darkroom work tougher. Even if you shoot at EI200, that doesn't necessarily mean you should adjust development.

    Forth, with my FM2 when I was shooting to the shadows I needed to be quite careful to exclude everything but the shadows from the viewfinder to get reliable readings to work with. My incident meter was much better at getting me good negatives until I really got to understand what the FM2 was telling me.
    Mark Barendt, Beaverton, OR

    "We do not see things the way they are. We see things the way we are." Anaïs Nin

  3. #13

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    With a short-toe film like this, it's really important to know exactly where your deepest reproducible shadows lie in relation to the rest of the
    subject luminance. Working with a spotmeter is a big advantage.

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