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  1. #1

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    Efke film reciprocity

    I will be shooting some Efke PL100 4X5 sheet film during an upcoming trip. I expect do do some shooting in the early morning and late afternoon light. Low light combined with stopping down the lens means I'll need to know how to adjust my exposures.

    Anyone have experience with Efke reciprocity at certain metered times?
    Noel Cummings

  2. #2
    dr bob's Avatar
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    Quote Originally Posted by hblad120
    I will be shooting some Efke PL100 4X5 sheet film during an upcoming trip. I expect do do some shooting in the early morning and late afternoon light. Low light combined with stopping down the lens means I'll need to know how to adjust my exposures.

    Anyone have experience with Efke reciprocity at certain metered times?
    I have a "brick" of Efke R 100 (120) to experiment with - never having done so previously. Practical information on reciprocity and other technical "stuff" would be helpful.

    BTW, I commend J&C on their operations. May other APUGers consider doing business with them as well.
    I love the smell of fixer in the morning. It smells like...creativity!
    Truly, dr bob.

  3. #3

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    I haven't shot tons of Efke, but I have gone through 90% of a box of 8x10, with most of it shot over 1 second. These are the adjustments that I've been using.

    1"=2", 2"=5", 4"=15", 8"=35", 15"=1'30", 30"=3'15", 60"=8'45"

    Reciprocity adjustments are a funny thing. When I look at Francesco's technical data attached to his photo uploads I see exposure times that do not match mine. He has a much better handle on the intricacies of Efke film. You might ask him.

  4. #4
    Ian Grant's Avatar
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    Well shooting recently with the slower Efke PL25 I assumed reciprocity would be a problem, and dounled the exposures, around 60 seconds @ f 45.

    In fact I was being over pessimistic and the negs were a touch over exposed

  5. #5
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    Ian, for all of Efke 25's unforgiving qualities, reciprocity is not one of them. Andrew O'Neill did his own tests and had the following, which I found is correct with my equipment. Thanks Andrew.

    1 second on meter = +1/6 stop
    10 seconds on meter = +1/3 stop
    100 seconds on meter = +2/3 stop
    Matt, remember Francesco is using BTZS times for development, so his SBR numbers have a lot to do with expanding and contracting development along with exposure variations, bellows extension and any filters he may be using. This may be why your numbers look to be different.

    Perhaps the Professor of 8X10 can give us a short lesson on Efke 100 reciprocity?

  6. #6
    c6h6o3's Avatar
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    Quote Originally Posted by noseoil
    1 second on meter = +1/6 stop
    10 seconds on meter = +1/3 stop
    100 seconds on meter = +2/3 stop
    That's less than what you give 400TMax, which is:

    1 second indicated: +1/3 stop
    10 seconds : +2/3 stop
    100 seconds : +1-1/2 stops
    Jim

  7. #7

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    I dont really have reciprocity rules or adjustments when it comes to Efke PL100 (or Classic 400, my other film of choice). I base my exposure on varying SBR levels that I encounter. For example, if I measure the low EV to be 2 and high EV to be 10 and I want to stop down to say f. 64 I would expose for about 25 minutes. How I came about his is through trial and error (mostly) and interpolation from other SBR levels. I find this to be more exact than simply having the meter tell you how long to expose and then add on extra stops for reciprocity adjustments. I would also point out that my exposure and development times are specifically tailored to printing on AZO paper, and would certainly result in negatives that are too dense and contrasty for enlarging paper.
    Francesco

  8. #8

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    The APUG community never ceases to amaze me with their depth of knowledge on a variety of subjects.

    How about rating the film? What speed do you all rate Efke PL100...50, 40, etc...?
    Noel Cummings

  9. #9

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    Quote Originally Posted by hblad120
    The APUG community never ceases to amaze me with their depth of knowledge on a variety of subjects.

    How about rating the film? What speed do you all rate Efke PL100...50, 40, etc...?
    That depends on what your negatives will be printed on. If Azo then Efke Pl 100 will be properly exposed at 80-100 if you are making negatives for silver enlarging then I would expose this film at 50.

  10. #10

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    Donald, thanks for your reply and for pointing out two very different outcomes. I shoot to enlage on silver.

    Thanks
    Noel Cummings

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