Overexpose and Underdevelop?

Discussion in 'B&W: Film, Paper, Chemistry' started by Kevin Kehler, Jul 25, 2008.

  1. Kevin Kehler

    Kevin Kehler Member

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    A question regarding exposures and developing, which while stemming from the Zone System, is not meant to mean that I am using that system. I recently borrowed several books from the library and have done some research on-line about negative development; a common suggestion is to overexpose to allow for shadow detail and then under-develop to save highlights. This should increase contrast and allow better prints; I also realize that all shots on a role of film would have to be exposed/developed the same amounts. My question is how to calculate these types of scenarios.

    I am using a Minolta Spotmeter (digital) so I am able to have very accurate measurements and can have 1/3 or 1/2 steps in ISO (i.e., I usually expose Velvia 50 at 40 as I like the colour and highlights better but I don't develop E-6 myself). I like using PanF, which is a 50 ISO, and then exposing at 25 ISO so there is an over-exposure already; however, looking at the development times (1:1 Perceptol), there is a 4:30 difference between 25 and 50 (I have been following recommended development times so far). HP5+ has a 3 minute difference in ID-11 between 400 and 800 ISO.

    So, how does one decide how long to leave the roll in the developer?
    __________________
     
  2. Rich Ullsmith

    Rich Ullsmith Subscriber

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    Hi Kevin. First off, know that many folks that try different films ask this question on every roll! (I do.)

    Regarding your spot meter: I recommend carrying a 15% gray card to read off, unless you plan on spotting the whole scene to see how many stops you need.

    Regarding your development: Do whatever necessary to be consistent with your agitation schedule and temperature. If you vary either of these, you can never really know the reason for your results, good or bad.

    Recommended times and dilutions are starting points. It's boring as hell, but the best thing I've found is to put my grey card in a scene and shoot a roll and see what happens. If you plan on spending time with the PanF+, I really think this a good idea.
     
  3. dancqu

    dancqu Member

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    Under development will Decrease contrast. Dan
     
  4. smieglitz

    smieglitz Subscriber

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    As will overexposure (or underexposure for that matter). Overdevelopment is the only one of the 4 that increases contrast.

    If you are in a high contrast lighting situation (bright sun w/ hard-edged, distinct shadows, etc.), then you might consider pulling the film as you suggest. For other lighting contrasts I would not recommend the OE/UD route.

    Pulling is usually recommended only when you have mixed lighting situations on the roll or if for some reason you would want finer grain at the expense of film contrast.

    Testing is the only way to discover how long to develop.
     
  5. Rick Jones

    Rick Jones Member

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    If your important highlights print as you intended on the paper grade you intended your development time for that particular scene is correct. If highlights are too gray development time is too short. If highlights are so light in tone that little or no detail shows development time is too long. With practice you can use your spot meter to determine the spread between important shadow detail and highlights in order to tailor development. Otherwise, you are resigned to pick a development time that allows the majority of frames to print satisfactorily by changing paper contrast and or with dodging and burning. I would recommend against arbitrarily choosing to expose Pan F at 25. Expose at the E.I. that produces the shadow detail you want. Exposing Pan F at 25 may not be over exposing the film. It may be exposing it just right. Developing for times shorter than those recommended by Ilford may not be under developing at all. The shorter times may be just right for your conditions.
     
  6. Thomas Bertilsson

    Thomas Bertilsson Subscriber

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    1. Exposure determines shadow details. Take a roll of film and expose it in the kind of lighting you are most likely to work. Bracket plus and minus one stop. Develop normal.

    2. Examine these negatives, or better yet - print them, and see which of the negatives give you the shadow density you want. Forget about highlight for now.

    3. Expose another roll at the setting you decided gave best shadow details.

    4. Cut roll in thirds. Develop one third at 25% less than the recommended time, one third at the recommended time, and the last third at 25% more than the recommended time.

    5. Examine these negatives, and see which gives both highlight and shadow densities you seek.

    With two rolls and some work you have tested to see what camera/meter settings and developing duration you need to get what you want. It really is that simple.

    Your camera's shutter accuracy, your meter's accuracy, your metering technique, the developer, developer dilution, developer temperature, agitation, even local water quality - all of these factor into your end results and is a unique set of parameters for your method. Nobody else does it exactly the same way.
    Think about that.

    My philosophy - underexposed, overexposed, underdeveloped, overdeveloped - these are all relative terms. Find the combination of exposure and development that works for you and you have - perfect exposure and perfect development. Nothing else matters.

    - Thomas
     
  7. Kevin Kehler

    Kevin Kehler Member

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    Thanks everyone for your comments. My problem is that I really like the PanF+ pulled + Perceptol combination because of the superior fine grain that is achieved but I am have a terrible time with contrast, as in not enough. I am currently working on a series of shot on abandoned farmhouses, so I am indoors with natural light, at 25 ISO, leading to 15-30 second exposure times as a norm. I think I am going to have to follow Thomas' suggestion and determine in a more accurate fashion what it is that will work for my project. I know I could go with a faster film to increase the contrast but I was hoping to do the project all with the same film/developer. That might just be an unrealistic expectation.
     
  8. Matthew Gorringe

    Matthew Gorringe Member

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    PanF+ is not known as a film with very wide exposure or development latitude. That means it can be more difficult to achieve acceptable results by guesswork than with other films. If you want to continue using PanF+ it could be helpful to at least test for your own EI. If you give more exposure and less development you are always reducing contrast.

    If it's the fine grain you like try Delta 100 or TMax 100. Perhaps start with the box speed and recommended development times. If you then want a little more shadow detail reduce the speed. If you want more contrast increase your developing time.
     
  9. gainer

    gainer Subscriber

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    Overexposure is a less serious error than underexposure. Overdevelopment is a less serious error than than underdevelopment. If you claim not to know this from experience, shame on you for lying to your elder.

    It's pretty obvious that detail that slides off the bottom is gone for ever. At the other end, a print made of an underdeveloped negative on grade 3 or even 4 paper is usually better than a print of the same scene made from an overdeveloped negative on grade 1.

    That rule is so old that it may have been inspired by the use of printing out paper, which loves overdeveloped negatives.

    Part of my photographic education has been learning how much leeway there is in these technicalities. I'm sorry to say that it all boils down to that first paragraph. David Vestal puts it "Expose generously. Don't develop too much. Make mistakes to find out how much is too little exposure and too much development." That's not an exact quote, but it's close enough for government work as we used to say at NACA.
     
  10. dancqu

    dancqu Member

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    Mr. Gainer, you contradict. Dan
     
  11. Robert Budding

    Robert Budding Member

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    Are you correcting for reciprocity failure for those 15-30 sec exposures? If not, you will underexpose and end up with flat negs.
     
  12. Kevin Kehler

    Kevin Kehler Member

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    As much as I would like to say "of course", this might be a significant factor as I probably forget more often than not. When I find the time to do the development tests (hopefully this week), I will have to take this into account now and in the future besides TATTOOING IT ON MY FOREHEAD!:D
     
  13. Robert Budding

    Robert Budding Member

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  15. gainer

    gainer Subscriber

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    To learn about reciprocity, go to www.unblinkingeye.com and look for the article "LIRF is lurking at your F-stop".
     
  16. RobC

    RobC Member

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    There is a persistent myth that over exposure is required to get good shadow detail. This is not necessarily true and entirely dependant of subject contrast range. AA is known primarily as landscape photographer where very often he has bright clouds and dark shadows in the images and where the subject contrast range is great. Result is that he uses a 10 zone system and to make a 10 stop subject from black to white fit onto a negative which then fits directly to paper, you need to overexpose and reduce development from manufacturers recommended times.
    So what are manufacturers recommended times based on? Well, usually around a 7 stop range for negative films. That is based on the "average subject" brightness range and not high contrast scenes.
    So now take your subject and find out what its range is. You have a spot meter so that should be easy to determine. Since it is indoors I strongly suspect it will be a low contrast subject. Very probably less than 7 stops from black to white unless you have windows or shafts of sunlight coming into the image. For a 7 stop or less subject range you should not be giving additional exposure so expose at ISO speed and use manufacturers recommended times. That will give you the contrast in the negative which will fit the paper.
    If you are still getting low contrast negatives, then increase development time 30% and try again and if you are still getting low contrast negatives, then go to ISO 60 or above.

    As you know the zone system as says there are zones 0 thru 10. By default each of those zones is 1 stop of exposure. However, the zone system is so flexible that if you have a subject of say only 6 stop range from black to white, then you can say each zone is 1/10 of that range. That would make each zone step 0.6 stops. That means that if you meter what you want on zone 3, then you would reduce exposure by 1.2 stops or 1 1/3 which is close enough. This assumes you have tailored development of your film to fit a 6 stop range.
    The same applies for slide film except slide film is high contrast film and out of the box it accepts only 5 to 6 stops brightness range from black to white. Assume 5 stops and therefore you can say each zone is 1/2 stop step. So if you meter what you want on zone 8 then you open up 1 1/2 stops to expose it correctly. A little trial and error is required but that will be pretty close.

    So to recap, high contrast scenes need extra exposure and reduced development from manufacturers recommendations (based on a manuafcturers 7 stop range).

    Normal contrast scenes require use of manufacturers recommended numbers and low contrast scenes require reduced exposure and increased development.

    But all of these require knowing how long to develop for.

    For b+W films you should do some print tests:
    To calibrate for a 10 stop subject range. Expose an even subject at zone 1 and then the same at zone 9 using 1 stop for each zone step. Print the zone 1 neg until it is just slightly less dark than a max black. Then print the zone 9 neg using the same print time and it should have just a hint of grey.
    If its white then reduce development a little (20%) and try again. Iterate until you nail it.

    To calibrate for a 7 stop subject range. Repeat the above except make each zone a 0.7 stop step. So exposing for zone 1 would be metered value and then closed down 4 x 0.7 = 2.8 stops ( a little over exposure is best so make it 2.66 stops. i.e. 2/ 2/3). Then expose a zone 9 neg which will be plus 4 x 0.7 from metered value. or rounding up for a little over exposure makes that + 3 stops. And print as above.

    To calibrate for a 5 stop subject range. Repeat the above except make each zone a 0.5 stop step. So exposing for zone 1 would be metered value and then closed down 4 x 0.5 = 2 stops. Then expose a zone 9 neg which will be plus 4 x 0.5 = 2 stops from metered value. And print as above to prove development is correct.

    Note that a zone 1 neg should have a small amount of density greater than the fb+fog. If the zone 1 neg is same as fb+fog then you need extra exposure (reduce film speed). If zone 1 neg is too dense then less exposure is required (increase film speed).
     
  17. dancqu

    dancqu Member

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    Follows is my understanding.
    Reciprocity's failure applies to those portions of a scene
    who's level of lighting falls below some minimum. The failure
    is non-linear and accelerates. So dropout increases
    disproportionately with lowering light levels. An
    increase in contrast occures in those low
    level lighted areas. Dan
     
  18. Anscojohn

    Anscojohn Subscriber

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    I would expect that the contrast range in those abandoned farmhouse interiors would be well within the limits of normal exposure and normal development----so long as you are not interested in detail in any kind of outside areas, such as outside the windows or doors. If, as I surmise, you are underdeveloping in an attempt to hold detail in those outside areas, or areas very close to the windows and doors, of course the remaining tones are going to be "flat."
     
  19. Steve Sherman

    Steve Sherman Subscriber

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    Well said!

    I was never comfortable with the terms Over or Under anything. This gives the implication that there is a known which over and under relate too.

    Maybe to a degree in color neg. / pos. material but not in B&W.

    My way of thinking is More exp. Less dev. and vice versa.

    Determine what tonalities you want in the final print and learn the techniques necessary to effect those tones and you'll never under or over anything again!
     
  20. Kevin Kehler

    Kevin Kehler Member

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    I thought I would show you some of the problems. This is PanF+, 25 ISO, 8 seconds at f/11, developed in 1:1 Perceptol for 10:30 minutes and then scanned into PS to do what I could with the negative (my darkroom is currently in storage due to space).

    [​IMG]

    Another problem shot, HP5+, 400 ISO, 1/60 at f/8, developed in 1:1 ID-11 for 13 minutes and scanned into PS.

    [​IMG]
     
  21. RobC

    RobC Member

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    From the times and developer concentrations you have used it looks as though you have used Ilfords own figures which is fine. You say you have not enough contrast but the contrast looks OK to me. However, the shadows look a little too low which begs the question "How did you meter these subjects?"
     
  22. Robert Budding

    Robert Budding Member

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    I really love the flexibility of B&W film. You can decide where to place tones, and you can expand or contract overall contrast to create whatever negative you want (but watch the local contrast, too). I don't classify this as myth - it is fact.
     
  23. phenix

    phenix Member

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    I’m afraid your problem is not the exposure and/or processing, but your monitor calibration.
    Exposure and contrast are fine, so must be the development.
    Still, if your expectances are higher, remember these images are only negative scans, not prints or print scans, so this must be the best you can get until you find a place for your darkroom.

    Besides, I love your first picture here above: composition and lighting, tones (all) and textures, contrast and mood, everything is beautiful!
    In the second one, I totally dislike the central composition and the flat light providing not much textures. But contrast and tones are still there. Would I have chosen, just for the mood, to replace the lake of textures with more grain? - Maybe, but with this subject I cannot be sure. First, I would have changed the composition, and only after I would have looked back into the mood and the technical options to emulate it.
     
    Last edited by a moderator: Jul 28, 2008
  24. Richard Jepsen

    Richard Jepsen Member

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    The quote from Vestal is "right on".
     
  25. RobC

    RobC Member

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    I think phenix has a point. A typical consumer scanner these days has a Dmax of 3.5 to 4. A typical B+W neg has a Dmax of around 1.5. That means it will always look soft when you scan it unless you adjust levels in the scan. So that means judging contrast from a scan is only good for scanned prints and not printing to paper. Unless you have calibrated your scans.
    But the shadows still look a little dark to me and a little more exposure would push them up the curve and increase shadow separation.
    That is why I asked how the metering was being done.

    Note that the shadows are the thin part of the neg so what you get on the scan should be fairly representative of what you would get in a print. Its the highlights which are likely to look flat on the scan but it does depend how you do your scan.
     
  26. Kevin Kehler

    Kevin Kehler Member

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    I am using a Spider2 colour calibration system for monitor calibration, so while it is possible it is my monitor that is wrong, I suspect not (I recalibrate once a week). I tend to meter by one of two methods, either by placing an 18% gray card in the scene and reading from it or by using my meter's highlight/shadow function by finding the darkest/brightest part of a scene and metering from there. I like to see the picture in my head prior to pushing the shutter, knowing whether the emphasis will be shadows, highlights or somewhere in between. I have never worked with the Zone System as: (1) my initial photographic instructor thought it to be a waste of time and never encouraged anyone to study it and; (2) given that I shoot medium-format (as opposed to large format), my understanding was that it would require the entire roll to be exposed along very similar lines otherwise the development process would erase any gains made from the exposure calculations. Perhaps my assumptions/training are wrong (it wouldn't be the first time) and I need to study more.

    When I scan a negative, I adjust the levels prior to the scan to encompass all light points present, which leads to a flat scan but gives me maximum information in the Tiff for when I adjust levels after the scan. While I appreciate your comments Phenix, to my eyes, the first shot has large dark splotches that don't seem to have details and second shot is a series of gray areas. Perhaps I am being overly picky but I have never found that to be a bad thing (in photography, of course).