Can you compensate for underexposed negs with extended development?

Discussion in 'Exposure Discussion' started by Jim Moore, Nov 24, 2004.

  1. Jim Moore

    Jim Moore Member

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    I developed a couple of 8x10 negatives last night taken at the Zion workshop and they look like they might be underexposed by a stop of so.

    I was using a G-Clarion 240mm lens in a NEW copal 1 shutter and I fear that I may have screwed up when I made the f/stop scale resulting in underexposed negatives shot with this lens.

    I'm going to develop one more negative taken with this lens to try and verify if there is a problem.

    If the next negative does turn out underexposed would it help to extend the development time on the others?

    If so how much should I increase the development time?

    Thanks!

    Jim
     
  2. glbeas

    glbeas Member

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    You would just raise the contrast without really bringing up much shadow detail. The best bet would be a compensating developer like D-23 or something like Acufine or Ethol to get the speed without raising the contrast too horribly much.
    As for pushing, for the average developer I'm told it's add 20% for each stop push. I couldn't tell you what that means in N+ numbers.
     
  3. Eric Rose

    Eric Rose Subscriber

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    exposure is for shadows and development is for the highlights. A compensating development regime is probably your best bet. Maybe something with a bit of a punch in the first developer and then a more gradual second development. I've heard some people using HC110 and pyro in this way.
     
  4. Francesco

    Francesco Member

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    It all depends on the contrast range of the scene you photographed. If you remember it to be quite flat then your underexposure could be compensated by increased development resulting in a negative with enough acceptable contrast. If it was a scene of a high contrast then your underexposed negatives with over development will simply result in more density without detail and contrast.
     
  5. Alex Hawley

    Alex Hawley Member

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    Francesco stated it correctly regarding negative development. If you are contact printing on Azo, then there is probably enough latitiude to still get a decent print on grade 3 with what appears to be an undexposed negative.
     
  6. Donald Miller

    Donald Miller Member

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    If I read what you are saying correctly then the aperture scale is suspect. The way to determine this is to measure the aperture opening and divide this into the focal length of the lens. That should get you into the ball park of the correct aperture of the lens at the various Fstops.

    Unfortunately if you have inadequate shadow detail then there really is nothing that I have found that will give film exposure at the development stage. The film will expose at the proper amount of light. If that isn't present at the time of the exposure then no amount of development compensation is going to impart one bit of light.

    As others have related, contrast can be adjusted by development. Exposure can not be adjusted by development.
     
  7. mikewhi

    mikewhi Restricted Access

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    Sounds like the nut behind the tripod needs adjustment. Everyone does it, close down instead of opening up, vice versa, etc. Basically, if the photons from the dark areas of the scene didn't hit the film enough, no development increase will help - you can't develop silver halides that weren't exposed. If they did receive some exposure and the scene wasn't too contrasty, you'll improve things by increeasing development. If the scene was contrasty, you'll still build up more density in the lower areas but the higher values will increase proportionally more and you'll end up with a negative with a lot of hot spots. A proportional reducer would help here. So would masking. If these are really important negatives, the best thing would be to test this. Setup a scene at home with the same contrast range, underexpose by one stop and expose several negatives this way. Then, develop each for increasingly longer times, like +20%, +40%, +60% and see how the densities build up and make sure the total DR is within the capabilities of your paper. I've done this a few times and it really saved my bacon by taking the guesswork away from determining a development time.

    -Mike
     
  8. Ole

    Ole Moderator Staff Member

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    The best bet is a speed-enhancing developer like FX-2, Neofin Blue, Beutler or any of the several others on the market or the recipes. It is possible to combine these with a staining second developer, I have used Neofin Blue and Pyrocat-HD with good results and a full stop speed increase.
     
  9. David A. Goldfarb

    David A. Goldfarb Moderator Staff Member

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    What film are you shooting? If you're shooting one of the T-Max films, you might just process normally and still have usable shadow detail. Intensify in selenium if you need more contrast.

    If you're shooting a traditional film, I'd go with those recommending a speed-enhancing developer. Acufine will give an honest one stop of real speed increase in my experience (a little less than they claim), measured as shadow detail (or Zone I density of 0.1). The neg might be on the thin side at the highlight end, so you can print a grade higher than you usually do and/or use selenium intensification to push up the highlights.
     
  10. esearing

    esearing Subscriber

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    What would happen if he did a second (1-stop) exposure of a pure white background. Would it merely brighten contrast without enhancing shadow detail? I've always wondered...
     
  11. Donald Miller

    Donald Miller Member

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    I don't know what post flashing would do...I do know that pre flashing does wonders to support low values. I would certainly try a post flash exposure to non image bearing light at a Zone III or IV exposure. You have absolutely nothing to lose in trying this.
     
  12. noseoil

    noseoil Member

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    If there were adequate notes taken for the scene, a decent guess would be to add light in the form of a gray card exposure. As Francesco has mentioned, the scene brightness range is critical. Can you take a test shot with a step wedge, first, to see what the actual values are for an accurate shutter estimate of underexposure?

    With good notes taken of the scene, a known value of underexposure from the shutter and a bit of thought, this may not be too bad. If you can get a reading for the shutter from a step wedge (use the same f stop as the original shot to cut down on variables) you will know exactly how much your underexposure is.

    From this test and your notes, you should be able to get an idea of a flash exposure to boost the shadows sufficiently. At that point, it is only a matter of development time for nailing down the top for zone VIII. Please let us know how you fare with the process. Chin up buddy, we've all done things like this. The trick is learning from them. Best wishes for a successful development. tim
     
  13. Jim Moore

    Jim Moore Member

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    Thank you all for the information. As always so many around here willing to help. It is very much appreciated. :wink:

    I developed 2 more 8x10's tonight. Kodak TMAX400 in Pyrocat HD 1:1:100 in JOBO expert drum (I should have mentioned this in my original post)

    Looking at these negatives (and the ones from the other night) they look "thin", but there is detail in the shadow areas. Not as much as I would like, but there is some.

    I'm thinking that I should be able to get some good prints from them. They are probably to thin for AZO, but as long as I can get a good print I'll be happy.

    Thanks again,

    Jim
     
  14. noseoil

    noseoil Member

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    Jim, since they are on the thin side, give azo a try anyway. I've had this one to deal with and my technique for a thin negative is to give more exposure and then cut development time. I treat azo like a slow film. To reduce contrast you can try adding exposure and reduce development. The increased exposure treats the high values with enough light to make it through the film and get substance in zone VIII (remember, it is all backwards with paper). The reduced development time stops shadows from blocking up completely and turning to tar.

    It has been pointed out to me that this is not the correct way to deal with film. It should be the correct exposure and always match the paper's scale. Since I have made mistakes from time to time in my photography, am not perfect and have no real hope of being perfect on each shot, I've had to adapt to my own flaws (rationalization, justification or reality). I hope this isn't too discouraging, but it helps to realize that, try as we might, it isn't always as we wish. So what? As long as we keep plugging away, we will always learn and improve.