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  1. #1

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    I need help for Infrared problem

    hi. I'm Dongjoo Kim. student who studying photography in korea. I Plan to take a infrared photo in this summer vacation. today, I shoot first roll of my Rollei infrared 400 film. after develop, I found my flim is VERY transparent. Theres no image on the film. but the end of the film(Part of the film that came out from film magazine) is black. I think this means developer is worked. I don't know what's wrong. Can you help me?
    I use Rollei infrared 400 @ ISO 25, cheap infrared filter(massa IR 760), Minolta dynax7 body and Sony 24-70ZA. Developed 6min D-76(stock).

  2. #2
    MattKing's Avatar
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    Hello moonwindrial - welcome to APUG.

    I'm not sure the Rollei 400 has enough sensitivity to near-infra-red to permit use of an IR 760 filter.

    In my case, I have had most of my success with the Rollei 400 using an IR 720 filter and metering using a hand meter at EI 3 or EI 6.
    Matt

    “Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”

    Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2

  3. #3

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    Thanks for help, MattKing. I will try 720 filter.

  4. #4
    polyglot's Avatar
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    How long were the exposures? With a 760nm filter, they would need to be very long indeed.

    I also use a 720nm filter (R72) but with Efke IR820. I shoot that at EI1, i.e. f/16 for 1s in full sun. Rollei 400 would probably work at about EI4 with an R72 (1/4s f/16 full sun).

  5. #5

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    Normal exposure(Metered without filter, E.I ISO 25) was F11, 1/15s. today was very sunny day. I took a photo at 1pm. I tried exposure bracketing. +3 stop ~ -3 stop. changed shutter speed only.

  6. #6

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    Rollei IR-400(S) is going down in sensitivity over 750nm rapidly. So you need a 715nm or 720nm IR filter. Then you have to expose around iso 6-12 depending on the IR circumstances.
    When using an IR760nm filter no bandwith is left for the film.

    The Efke IR820 is a bit more sensitive over 750nm. But the regular speed of this film is iso 100 only. When using above filters you have iso 1,5-3 left. Maybe with a 760nm filter and iso 0,5 you can have reasonable results.

  7. #7

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    Quote Originally Posted by moonwindrial View Post
    Normal exposure(Metered without filter, E.I ISO 25) was F11, 1/15s. today was very sunny day. I took a photo at 1pm. I tried exposure bracketing. +3 stop ~ -3 stop. changed shutter speed only.

    Take a shot @ the box speed without any filters, just to test and see that all's well with your camera and processing.

  8. #8
    Andrew O'Neill's Avatar
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    It's an exposure issue. You will need long exposures with that filter. Start with an EI (ISO) of 1.5. At f/11 on a sunny day, your exposure should be around 22 sec with reciprocity effect factored in. That's my experience, anyways. Keep good notes.



 

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