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  1. #1
    Dan Henderson's Avatar
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    IR film exposure advice needed

    I just exposed infrared film for the first time, as follows:

    EFKE IR 4x5 film through a #87 filter in bright sun

    Using the "sunny 16 rule" advocated by others here and at the LF forum, and manufacturer's recommendation of ISO 1, correct exposure should have been f/16 for 1 second. I wanted to use f/22 so gave 2 seconds + 1 second for reciprocity, total exposure of 3 seconds.

    Developed the film for 12 minutes in Jay DeFehr's "Obsidian Aqua" developer, agitating the first minute, then 10 seconds every 2 minutes thereafter.

    Negative is very thin. Shaded tree trunk has a tiny bit of detail. Green leaves in bright sun show just a little detail. Grass in bright sun in background have some detail but will not print anywhere close to white. Sky will probably print black.

    Properly exposed FP4 negative developed at the same time as IR negative has good detail and contrast.

    I suspect severe underexposure.

    I would appreciate any advice experienced IR users can offer.
    Thanks,
    Dan


    web site: Dan Henderson, Photographer.com

    blog: https://danhendersonphotographer.wordpress.com/

    I am not anti-digital. I am pro-film.

  2. #2
    TheFlyingCamera's Avatar
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    Dan - one possible source for the problem is the time of day at which you were shooting. There is less IR at high noon than there is in the morning and evening. Reciprocity compensation is not just one second, but it's a whole stop - you should have used 4 seconds, not 3. At that point, one second is a meaningful deviation (unlike a lot of my nighttime stuff where my exposures are 30 seconds +/-). Also, the 87 is a particularly strong filter - next time try something like a Hoya RM72 that also transmits some visible light. The 87 has a cutoff of 800nm - your Efke loses sensitivity past 820nm - if you want detail in your image, you need either greater IR sensitivity or a filter with a lower cutoff point. Boosting exposure with the 87 will not get you a lot more tonal range - you'll gain density but you'll still have a wickedly contrasty negative. Try an 89b or the aforementioned Hoya RM72, which has a cutoff point of 720nm.

  3. #3
    Brian C. Miller's Avatar
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    +1 on exposure and filter. I use a very deep red filter, either the Hoya RM72 or the B+W 092. The opaque filters are only really good with Kodak film.

    If you look at the curve for the Efke IR, that maximum IR response is actually extremely poor. So far nothing has come close to what Kodak gave us. Also, Efke IR isn't good for reciprocity, so for your initial testing, be sure to bracket liberally, like N, N+1, and N+2.

    I really haven't seen a true correlation between available light and IR. Sure, in direct sunlight you can usually know what happens, but sometimes it really gives a suprise. I have a strip of Konica IR, and I used it in some deep woods, where there was no direct sunlight. The IR light made the pine needles look ghostly white, even though I was sure the IR would be negligible.

    You'll have to run some experiments for yourself to see how it behaves. Prepare to use at least ten sheets for that.

  4. #4
    polyglot's Avatar
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    The recommendation of ISO1 applies to use of an R72 filter with 720nm cutoff and only in Sunny-16 lighting (full sun). However you used an 87 which has the cutoff somewhere around 790nm so you're getting a much much narrower spectrum onto the film and will therefore need a lot more exposure. 720-800nm is the range where IR820 has most of its sensitivity and you've lost much of that with your filter choice.

    Get an R72 filter instead, even if it's a cheap chinese clone. Or you could add maybe 4 stops of exposure when using the #87 but you're well into reciprocity failure and it's all a bit annoying.

  5. #5
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    Hi Dan, Here's my goofy method. I set my meter for 320 iso, meter the Ev in the green which I want to affect and the range is as follows: at ev8 it's 3 minutes @f 22.5 on one sheet and 4 minutes on a second sheet. At Ev10, it's a minute with a second sheet at a minute 20. at EV15, it's 20sec. and 35 sec. for a second sheet , all at f22.5. It works and I never miss exposure..Bracket it as I describe and get the feel for it. I am using a B+W 092, so ot might be different but over exposing isn't a problem while underexposure is..TTYL, Evan

  6. #6
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    [QUOTE=Brian C. Miller;1382542+1, and N+2.

    I really haven't seen a true correlation between available light and IR. Sure, in direct sunlight you can usually know what happens, but sometimes it really gives a suprise. I have a strip of Konica IR, and I used it in some deep woods, where there was no direct sunlight. The IR light made the pine needles look ghostly white, even though I was sure the IR would be negligible.
    [/QUOTE]

    You have to remember the leaves are bouncing and passing a lotta IR so the proportion of IR to visible in such an environment is much higher. If it was another type of material shading the area you would likely have a totally different result.
    Gary Beasley

  7. #7
    DWThomas's Avatar
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    Hmmm - I would say leaves reflect a lot of the IR, thus the cotton candy look for trees, so there might actually be less underneath them. In any event, I remain convinced there is no substitute for bracketing!

    Just put two rolls of Rollei 400 IR through my Yashica 124G, using a TLR was much easier than the Bronica used in previous outings. Just slap that filter on and leave it there!

  8. #8
    Brian C. Miller's Avatar
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    Well, the thing is that conifer trees, i.e., spruce, pines, etc., don't reflect as much IR as deciduous trees and lawn grass. I have shots on Konica where the conifers are looking like some kind of grey scale, from light grey to black. But in that particular instance, the needles were just bathed in that fabulous look that I usually only got with Kodak HIE.

  9. #9
    Dan Henderson's Avatar
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    Thanks everyone for the great advice. Sounds like the first thing I need to do is go filter shopping!
    Dan


    web site: Dan Henderson, Photographer.com

    blog: https://danhendersonphotographer.wordpress.com/

    I am not anti-digital. I am pro-film.

  10. #10

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    Infrared film photography is hard. I used to pride myself on being able to expose slide film perfectly every time after years of practice. The normal rules simply don't apply with IR and it was a humbling experience when my first roll of Efke 820 came back completely blank. I agree with DWThomas; bracket the hell out of it until you learn to "see" with IR film (I'm not even close to that point, alas).

    Oh, and here's a link to the Efke 820 datasheet, via Freestyle: http://www.freestylephoto.biz/pdf/MACO_IR820c_AURA.pdf

    There are plenty of disclaimers stating that experimentation is needed for best results

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