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Thread: Filtering for a deep red filter

  1. #11
    Les
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    Ex-Seattlelite living in PNW
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    Re: Filtering for a deep red filter

    If you don't want to test via use of film (+processing time), you could employ digital camera. But, it's good to know how film will behave. Case in point, I was at Bristlecone Forest and the bright area of the tree would change the dynamics; therefore, one has to adjust to certain subject/s or even bracket it. Yes, I was using the red filter (B+W).
    Les

    On occasion I noticed there is real life outside the GG/viewfinder.

  2. #12
    Drew Wiley
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    Re: Filtering for a deep red filter

    Everything depends on the specifics. For example, what do you mean by deep red? 24A isn't as deep as a 25; 29 is deeper still, and some brands deeper than others. That variation could account for up to a stop and a half in filter factor variance.

    Some pan films are extended red sensitivity, some average, and then there is orthopan like Acros, only partially sensitive to red and essentially blind to anything beyond what a 25 will pass. And metering through anything deeply colored is just looking for trouble. There just isn't any substitute for testing in advance with each specific film and filter combination, and ideally under the same kind of lighting conditions you intend to use it.

    I got lectured all the time, even on this forum, why a deep red filter can't be used in the mountains at high altitude or all the shadows will go totally blanked-out black. Well, I've been successfully breaking that rule for the past 40 years, simply because I test for real-world filter factors and then place my shadow values appropriately during exposure. Works far better than conjuring Fred Picker from the dead and asking him about some film he never heard of, or trying to turn a digital camera into a light meter. I never bracket, except for testing new combinations. A little homework in advance saves a vast amount of headaches later.

  3. #13

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    Re: Filtering for a deep red filter

    To conjure Drew, I'll add that factors can change due to prevailing conditions and subjects... Like using that deep red on a "blue light" day, in open shade etc... That red filter will cut anything blue more, or green trees will darken considerably... Experience will be your guide...

    Even in sunny, bright SoCal, #25 and #29 filters take some care in use... And #47B also... The safest filters I find for general use are dark greens.... They put some tone in blank skies, lighten trees, and shadow areas are helped... Plus old lenses were generally well corrected to green in the ortho days, and film generally has great green sensitivity, so a good combo...

    Steve K

  4. #14
    Drew Wiley
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    Sep 2008
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    Re: Filtering for a deep red filter

    Takes some experience. Wind was relatively calm yesterday and I shot 3 4X5 sheets of TMY400 at a glassy estuary. Two directions with a 25red, another direction deep green filtration. Might sound like hard differences, but it will all come out quite subtly different in the actual prints. True color separation filters like deep blue 47 or 47B almost blacken both red and green. But few things in nature as quite what they seem to the human eye. Green foliage reflects a whole lot more than green, as both bees and IR film understand quite well. Fun stuff, that's for sure. But I think in terms of nuanced control, and hate any kind of overdone look.

  5. #15

    Join Date
    Feb 1999
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    1,094

    Re: Filtering for a deep red filter

    [QUOTE=Drew Wiley;1645129]Everything depends on the specifics. For example, what do you mean by deep red? 24A isn't as deep as a 25; 29 is deeper still, and some brands deeper than others. That variation could account for up to a stop and a half in filter factor variance.

    Some pan films are extended red sensitivity, some average, and then there is orthopan like Acros, only partially sensitive to red and essentially blind to anything beyond what a 25 will pass. And metering through anything deeply colored is just looking for trouble. There just isn't any substitute for testing in advance with each specific film and filter combination, and ideally under the same kind of lighting conditions you intend to use it.

    I got lectured all the time, even on this forum, why a deep red filter can't be used in the mountains at high altitude or all the shadows will go totally blanked-out black. Well, I've been successfully breaking that rule for the past 40 years, simply because I test for real-world filter factors and then place my shadow values appropriately during exposure. Works far better than conjuring Fred Picker from the dead and asking him about some film he never heard of, or trying to turn a digital camera into a light meter. I never bracket, except for testing new combinations. A little homework in advance saves a vast amount of headaches later.[/Q




    Drew, I’ve often tried coming conjuring Fred Picker from the dead, but he never answers me.

  6. #16
    Drew Wiley
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    Sep 2008
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    Re: Filtering for a deep red filter

    Oh, just fill an old top hat with some water and Zone VI modified Dektol, point your modified Zone VI meter that direction, look through the finder, and chant, It ain't workin', it ain't workin, the filter factor is wrong...want my money back... and see if the Dektol is boiling yet or not.

  7. #17

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    Feb 1999
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    Re: Filtering for a deep red filter

    If Fred Picker’s ghost ever showed up in my darkroom, he would tell me to find a new hobby.

  8. #18

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    Re: Filtering for a deep red filter

    Quote Originally Posted by Ben Calwell View Post
    If Fred Picker’s ghost ever showed up in my darkroom, he would tell me to find a new hobby.
    If he turned up in mine, he'd probably pass away again from laughter!

    Mike

  9. #19
    Drew Wiley
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    Re: Filtering for a deep red filter

    I'd hear the bottles rattlin' on his patent medicine wagon from a mile away, and just call the sheriff and a lynch mob before he fully came back from the dead.

  10. #20
    Alan Klein's Avatar
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    Re: Filtering for a deep red filter

    Changing the ASA setting on the meter is chancy when you forget to change it back after the shot and you change or remove the red filter.

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