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Thread: IR 760 filter - rating film speed

  1. #21

    Re: IR 760 filter - rating film speed

    i have the same filters (Green L 760 and 720) so far I got acceptable results using the 720 with Rollei IR 400 at an ASA between 3 and 6. I did not get any acceptable results with the IR760 filter yet but never tried beyond ASA3. Did you get any acceptable results with the IR760?

  2. #22

    Join Date
    May 2009
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    Vermont
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    184

    Re: IR 760 filter - rating film speed

    Quote Originally Posted by Pere Casals View Post
    In theory a DSLR sensor cannot see infrared because a NIR blocking filter is installed, the right exposure with a DSLR and a 760 filter won't give a clue about what exposure is required with Rollei 400 IR film because different practical factors are involved, with DSLR exposure depends on how good/bad is the NIR blocking, with Rollei 400 IR it depends on remaining sensitivity at +760nm.
    The M8 doesn't have the IR blocking filter, in fact when not using IR it is best to have an IR/UV blocking filter on the camera. Leica supplied them on request to those who bought the M8 new. Always liked a rangefinder camera with IR.

  3. #23

    Join Date
    Jul 2016
    Posts
    4,459

    Re: IR 760 filter - rating film speed

    Quote Originally Posted by Tom Monego View Post
    The M8 doesn't have the IR blocking filter, in fact when not using IR it is best to have an IR/UV blocking filter on the camera. Leica supplied them on request to those who bought the M8 new. Always liked a rangefinder camera with IR.
    Tom, the M8 has an IR/UV blocking filter, very thin, it is less effective in the deep reds that usual and a IR/UV blocking filter on lens may be suitable in certain conditions, but think that if the M8 not had the cut-off filter then images would be totally weird for regular photography.

    Compare the M8 spectral response with the KAF-10500 CCD sensor, and you will see what the UV/IR blocking filter does.

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