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  1. #1
    Kevin Kehler's Avatar
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    Reciprocity Failure, Highlights and Macro

    I am trying to do a fairly low-key B&W image with my 5x7 camera - it is of some orange-ish flowers in front of a black board, using light from a north-facing window and about a 2:1 magnification (i.e., the flowers on the ground glass are twice as large as in real life). If I spot meter off of the black board, the meter reads 60s @ f/64 which would give me 30s @ f/32 (my desired aperture for depth of field) for middle gray since I am adding 3 stops of light to get from Zone II to V. If I meter off a gray card, I get 30s @ f/32, so that is easy - however, I also need to add 3-stops due to bellow extensions, which gets me to 2m @ f/32 which translates into 12m @ f/32 once reciprocity failure is accounted for (I am using the formula from Way Beyond Monochrome to get the final number). I realize that I will need to do N-2 development to prevent too much contrast.

    However, thinking about this last night, I realized that reciprocity adjustments are there to maintain shadow detail, something that my still life has almost none. I want a pure black background (with no detail) but it is the flowers (on Zone VII) that are important. I am worried that even with the N-2 development, I will not have sufficient detail in the leaves since the highlights are building up so much more due to the long exposure. How much past Zone VII will the exposure push the leaves? IX? X? XI? In all three scenarios, an N-2 development will not give sufficient detail to these highlights. Should I perhaps shoot the flowers as Zone V, let the exposure push them to IX and then N-2 to bring them back to VII? Perhaps underexpose the negative, sacrificing the minute amount of shadow detail to prevent highlight blocking up? Or should I use a 1:100 Rodinal semi-stand development to control these highlights as opposed to D-76 1:1 in a rotary processor, which is my normal method?

    I hope I am making myself clear - what is the best way of ensuring my highlights are Zone VII given the lengthy exposure necessary?

    Lastly, I am somewhat guessing at the depth of field as the image on the ground glass is way too dark for me to make out, even with a loupe and a flashlight shining on the flowers (this light source will not be part of the final image). At f/5.6, I focused on the front flower, focused on the rear petal, adjusted the focus between the two and stopped down to f/32. Is there a better way of doing this?
    Once a photographer is convinced that the camera can lie and that, strictly speaking, the vast majority of photographs are "camera lies," inasmuch as they tell only part of a story or tell it in a distorted form, half the battle is won. Once he has conceded that photography is not a "naturalistic" medium of rendition and that striving for "naturalism" in a photograph is futile, he can turn his attention to using a camera to make more effective pictures.

    Andreas Feininger

  2. #2

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    If this is of any help. Last night I developed some 4x5 Ilford Delta 100 some of which was shot with a pinhole with exposures up to 10 minutes and some with my 4x5 with exposures up to 25 seconds and some less. I developed the film in Pyro PMK @70 degrees F for 22 minutes and got great looking negatives with what appears to be consistent densities even of the same subject which also happens to have been flowers -- tulips both orange and white ones. They were shot indoors with reasonably strong light coming through a sliding glass door but not the same day and with variations in the light. One was of a pineapple that is also in the color range you seem to have.

    http://www.jeffreyglasser.com/

  3. #3
    Kevin Kehler's Avatar
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    I am using FP4+ and don't have access to Pyro - although it is encouraging that you are getting consistent negatives. Perhaps I am over-thinking it?
    Once a photographer is convinced that the camera can lie and that, strictly speaking, the vast majority of photographs are "camera lies," inasmuch as they tell only part of a story or tell it in a distorted form, half the battle is won. Once he has conceded that photography is not a "naturalistic" medium of rendition and that striving for "naturalism" in a photograph is futile, he can turn his attention to using a camera to make more effective pictures.

    Andreas Feininger

  4. #4
    RalphLambrecht's Avatar
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    Quote Originally Posted by Kevin Kehler View Post
    I am trying to do a fairly low-key B&W image with my 5x7 camera - it is of some orange-ish flowers in front of a black board, using light from a north-facing window and about a 2:1 magnification (i.e., the flowers on the ground glass are twice as large as in real life). If I spot meter off of the black board, the meter reads 60s @ f/64 which would give me 30s @ f/32 (my desired aperture for depth of field) for middle gray since I am adding 3 stops of light to get from Zone II to V. If I meter off a gray card, I get 30s @ f/32, so that is easy - however, I also need to add 3-stops due to bellow extensions, which gets me to 2m @ f/32 which translates into 12m @ f/32 once reciprocity failure is accounted for (I am using the formula from Way Beyond Monochrome to get the final number). I realize that I will need to do N-2 development to prevent too much contrast.

    However, thinking about this last night, I realized that reciprocity adjustments are there to maintain shadow detail, something that my still life has almost none. I want a pure black background (with no detail) but it is the flowers (on Zone VII) that are important. I am worried that even with the N-2 development, I will not have sufficient detail in the leaves since the highlights are building up so much more due to the long exposure. How much past Zone VII will the exposure push the leaves? IX? X? XI? In all three scenarios, an N-2 development will not give sufficient detail to these highlights. Should I perhaps shoot the flowers as Zone V, let the exposure push them to IX and then N-2 to bring them back to VII? Perhaps underexpose the negative, sacrificing the minute amount of shadow detail to prevent highlight blocking up? Or should I use a 1:100 Rodinal semi-stand development to control these highlights as opposed to D-76 1:1 in a rotary processor, which is my normal method?

    I hope I am making myself clear - what is the best way of ensuring my highlights are Zone VII given the lengthy exposure necessary?

    Lastly, I am somewhat guessing at the depth of field as the image on the ground glass is way too dark for me to make out, even with a loupe and a flashlight shining on the flowers (this light source will not be part of the final image). At f/5.6, I focused on the front flower, focused on the rear petal, adjusted the focus between the two and stopped down to f/32. Is there a better way of doing this?
    admitedly, the contrast adjustments in WBMII are calculated theoretical valuesand could noy be verified in practical work flows.Isuggest tto you to spot meter your subject and place the most important parts of your subject according to the zone system.Let the rest determin your contrast treatment or let the remaining tonalities fall where they may. good luck, and don't forget to post the results.
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

  5. #5
    cliveh's Avatar
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    The exposure seems to be your main concern and as it is a still life (although flowers wont last that long) why not bracket several exposures with both changes in aperture and speed (you also seem concerned about DOF, keep notes), leaving your set up in place. Evaluate and re-shoot.

    “The contemplation of things as they are, without error or confusion, without substitution or imposture, is in itself a nobler thing than a whole harvest of invention”

    Francis Bacon

  6. #6

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    Quote Originally Posted by Kevin Kehler View Post
    ...If I spot meter off of the black board, the meter reads 60s @ f/64 which would give me 30s @ f/32 (my desired aperture for depth of field) for middle gray since I am adding 3 stops of light to get from Zone II to V. If I meter off a gray card, I get 30s @ f/32, so that is easy - however, I also need to add 3-stops due to bellow extensions, which gets me to 2m @ f/32 which translates into 12m @ f/32 once reciprocity failure is accounted for (I am using the formula from Way Beyond Monochrome to get the final number). I realize that I will need to do N-2 development to prevent too much contrast.

    ... I want a pure black background (with no detail) but it is the flowers (on Zone VII) that are important. I am worried that even with the N-2 development, I will not have sufficient detail in the leaves since the highlights are building up so much more due to the long exposure. How much past Zone VII will the exposure push the leaves? IX? X? XI? In all three scenarios, an N-2 development will not give sufficient detail to these highlights. Should I perhaps shoot the flowers as Zone V, let the exposure push them to IX and then N-2 to bring them back to VII? Perhaps underexpose the negative, sacrificing the minute amount of shadow detail to prevent highlight blocking up? Or should I use a 1:100 Rodinal semi-stand development to control these highlights as opposed to D-76 1:1 in a rotary processor, which is my normal method?

    I hope I am making myself clear - what is the best way of ensuring my highlights are Zone VII given the lengthy exposure necessary?
    Why meter and place your background in Zone V if you want it in Zone I or even Zone 0? Place the shadow/low values where you want them to be in the print.

    Then meter the highlights and see where they fall. If the result is "N" development, then simply follow the trail of bellows extension compensation, reciprocity failure compensation and development adjustment and you should get the result you desire. The development compensation related to the reciprocity failure adjustment takes the expansion of the highlights into considerations and compensates for them. You don't need to do anything else (assuming, of course, that you have a tested and working system for your film/meter/development for reciprocity failure compensation...)

    However, if you find an N- or N+ development is necessary before you start compensating for bellows and reciprocity, this "-" or "+" should be figured in to your final development compensation. Example, you want to expand contrast and choose N+1 development. After all the adjustments, you find that you need N-2 development for the reciprocity failure time you have chosen. Simply add N+1 and N-2 to get your final development time: N-1.

    If you place your "black" background on Zone V and do everything, you'll end up with a negative overexposed by 4 stops. (Plus, by placing shadows correctly, you'll likely have less reciprocity failure to deal with!)

    So, meter and place the background. Meter the flower and see where it falls. Determine a starting development scheme. Figure in all your adjustments. Adjust your final development scheme by your starting one.

    Best,

    Doremus



 

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