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  1. #11

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    By using a minus red filter (cyan) Wratten 44 or 44A on the camera any BW pan film delivers the same response as an ortho film. Of course this doesn't help if you want DBI convenience. But you do get the ortho look.

  2. #12
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    Hi Jason-

    I've used the Ilford Ortho with great success. Like the previous poster, it seems to actually be ASA20 or so when developed in Rodinal 1:50, 12m, 68F. Can send you a scan. I find it behaves tonally like FP4. Good shootin' down there!

    Russ

  3. #13

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    Another vote for Ilford Ortho -- which can also stand extraordinary overexposure and is ideal for high contrast processing for alternative processes.

    Cheers,

    Roger

  4. #14
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    In an email from J&C I was informed that the Efke 25 Ortho will be available in 11x14. If the price is reasonable, that will be very welcome news for those shooting 11x14 or making enlarged negatives, since the Bergger material is quite expensive, Ilford Ortho is non-existent in 11x14, and Agfa and Kodak no longer make their ortho copy films. I am crossing my fingers that the price will be good and that folks will not have to resort to special treatment of high contrast lith films (unless of course they prefer to do so).

  5. #15

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    Quote Originally Posted by JG Motamedi
    It does suck that Tri-X ortho is gone.
    you're telling me!

    i processed and printed many-a portrait on that with, and when my mentor passed away, the person who acquired her cameras, lenses, film paper &C &C, just dumped it all in the trash ( along with her other stuff he thought had no value ) ... olde tri-x and olde tri-x ortho, was the best ...
    Last edited by jnanian; 05-19-2006 at 05:23 PM. Click to view previous post history.
    silver magnets, trickle tanks sold
    artwork often times sold for charity
    PM me for details

  6. #16

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    Quote Originally Posted by Gerald Koch
    By using a minus red filter (cyan) Wratten 44 or 44A on the camera any BW pan film delivers the same response as an ortho film. Of course this doesn't help if you want DBI convenience. But you do get the ortho look.
    This is absolutely not correct. There is no way to filter a panchromatic film and duplicate the sensitometric characteristics of an orthochromatic material. One may diminish some of the red response...that reasoning makes the error that this will add orthochormatic response. That is simply not what occurs.

    An example by illustration would be to take popcorn and suppose that by failing to add salt one adds sugar...we all know that does not happen.
    Art is a step from what is obvious and well-known toward what is arcane and concealed.

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  7. #17

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    Quote Originally Posted by Donald Miller
    This is absolutely not correct. There is no way to filter a panchromatic film and duplicate the sensitometric characteristics of an orthochromatic material. One may diminish some of the red response...that reasoning makes the error that this will add orthochormatic response. That is simply not what occurs.

    An example by illustration would be to take popcorn and suppose that by failing to add salt one adds sugar...we all know that does not happen.
    Orthochromatic films typically have a spectral sensitivity extending from short wavelengths up to about 575 nm, panchromatic films up to 650 to 700 nm. In both cases the sensitivity curve isn't flat, with the response curve starting to fall before the long wavelength limit.

    So a panchromatic film has a broader spectral response than then orthochromatic films. You could think of it as the manufacturer having added to the panchromatic film, compared to orthochromatic film, spectral response from approx. 575 to 650 nm. You could undo this "addition" by using a filter that absorbs light with wavelengths longer than 575 nm and create a system of pan film plus filter that has approximately the same spectral response as ortho film. Converting pan film to ortho is subtracting response, not adding response.

    I can't make any sense out of the analogy to popcorn, salt and sugar.

  8. #18

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    Quote Originally Posted by MichaelBriggs
    Orthochromatic films typically have a spectral sensitivity extending from short wavelengths up to about 575 nm, panchromatic films up to 650 to 700 nm. In both cases the sensitivity curve isn't flat, with the response curve starting to fall before the long wavelength limit.

    So a panchromatic film has a broader spectral response than then orthochromatic films. You could think of it as the manufacturer having added to the panchromatic film, compared to orthochromatic film, spectral response from approx. 575 to 650 nm. You could undo this "addition" by using a filter that absorbs light with wavelengths longer than 575 nm and create a system of pan film plus filter that has approximately the same spectral response as ortho film. Converting pan film to ortho is subtracting response, not adding response.

    I can't make any sense out of the analogy to popcorn, salt and sugar.
    One can not duplicate an orthochromatic emulsion or in any way come close to it by filtering a panchromatic film. This has been discussed many, many times before and the reasoning is that you can not make something simply by removing somenthing else. That reasoning is not sound. Perhaps if you grasp the reasoning for this then you will grasp my earlier analogy.
    Art is a step from what is obvious and well-known toward what is arcane and concealed.

    Visit my website at http://www.donaldmillerphotography.com

  9. #19

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    Quote Originally Posted by JG Motamedi
    The Bergger film (anybody know who makes it?), like the Ilford is very expensive. Is it worth it?
    [size=2]Bergger:

    [/size][size=2]http://www.bergger.fr

    G[/size]

  10. #20

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    Dear Donald,

    Looking at the spectral response curves for a couple of older Ilford films -- FP4 pre-Plus and Commercial Ortho, because they were what I had handy -- I can't see why it should be impossible to come close to an ortho effect by using a filter with a T50 of about 570nm.

    Both start in the UV at around 360-370 with the residual halide sensitivity; climb slowly to the same peak at about 460; dip at around 500 (maybe 490 for Ortho); then climb again. Ortho climbs to a dye peak at around 560, then plummets, while FP4 has less pronounced peaks at around 600 and 640 before tapering off at about 660.

    I'm not arguing with you -- I don't know enough -- but I'd be grateful for an explanation.

    I should add that I've almost always found it easier to use the 'real thing' (e.g. ortho film unstead of filtered pan, or an 8x10 inch camera and uncoated lenses for Hollywood portraits) and that I've likewise found that 'coming close' is sometimes a long way from 're-creating'. My question is based on theoretical considerations only.

    Cheers,

    Roger

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