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  1. #11

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    Yeah, I think it would be something to explore. Hopefully I'll get some wratten filters soon, (perhaps 25, 58, 47, anyone have suggestions?) and do some colour separation work I've always wanted to do!

  2. #12
    Nikanon's Avatar
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    Color infrared is impossible with black and white film, there are no dye couplers in the emulsion to record individual colors, simply the silver halides (plus sensitizers) reacting with photons. Recording black and white film with different color filters will only give you different tonal relationships, but not record any color information.

  3. #13

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    I never used any EIR. It was just too darned expensive.
    Dave

    "She's always out making pictures, She's always out making scenes.
    She's always out the window, When it comes to making Dreams.

    It's all mixed up, It's all mixed up, It's all mixed up."

    From It's All Mixed Up by The Cars

  4. #14

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    Quote Originally Posted by Nikanon View Post
    Recording black and white film with different color filters will only give you different tonal relationships, but not record any color information.
    Yes, but that in itself is colour information!

    Indeed there are no colour couplers in b/w film, but we can take those tonal relationships and use them as the elementary makeup of a colour photograph. For example, if I took a b/w picture with a red filter, the film (assuming it's pan film) would therefore only capture the intensities of the colour red in the given scene (that's why the sky comes out black, because the sky is almost cyan - the opposite of red). Therefore, this "red b/w" image can be used as the red channel in a typical RGB image.

    Take a look at the dye transfer process. Having 3 different b/w pictures of the same scene separated by filters, they would be compiled to make a colour image. Technicolor was also based on this principle.

    Thats why I think it might just be possible to replicate EIR with 3 separation negatives. I was also just looking at the general spectral sensitivity of infrared film and I noticed it still has sensitivity in the blue/green area. So, I think the infrared exposure would have to be behind a red filter to block the green/blue spectrum.

    Okay guys, let's get the dye-transfer process going again! (Or we could just use PS to compile the channels)

    Edit: Does anyone know the spectral sensitivity of the infrared layer in EIR? Or what that layer actually captured?
    Last edited by happyjam64; 09-05-2010 at 01:19 AM. Click to view previous post history.

  5. #15
    Stephen Frizza's Avatar
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    This image was done via the technique mentioned above. This portrait of me was made by APUG member Goldie.
    Attached Thumbnails Attached Thumbnails portrait.JPG  
    "Its my profession to hijack time" ~ Stephen Frizza.

  6. #16

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    Quote Originally Posted by happyjam64 View Post
    Indeed there are no colour couplers in b/w film, but we can take those tonal relationships and use them as the elementary makeup of a colour photograph. For example, if I took a b/w picture with a red filter, the film (assuming it's pan film) would therefore only capture the intensities of the colour red in the given scene (that's why the sky comes out black, because the sky is almost cyan - the opposite of red).
    The sky is, as we all know, blue. Not (almost) cyan.
    And blue is indeed at the other end of the spectrum, and not let through by a (good) red filter.

  7. #17

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    To make the separation idea work, you'd need to shoot B&W IR film, of course. But otherwise it should be doable. Of course unless combined digitally you are probably looking at pin-registered neg carriers and easels to get prints to line up. And it would only work for static subjects.

    -Ed

  8. #18
    Stephen Frizza's Avatar
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    when certain things in the photo arnt static the results get really interesting!
    "Its my profession to hijack time" ~ Stephen Frizza.

  9. #19

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    Woah, cool portrait. Well, now we know it works, thanks Stephen!

    Just another thought here, what if we bi-packed an ortho film with some infrared film and have a red filter in between (assuming the ortho film didn't have an anti-halation layer)? So light would hit the ortho film and capture the green and blue. Then the red filter would block the green and blue and let the infrared film capture the red and infrared.

    Perhaps we could even apply the resulting negatives to this theory http://www.greatreality.com/Color2Color.htm

    I wonder what would happen...

  10. #20
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    Quote Originally Posted by Nikanon View Post
    Color infrared is impossible with black and white film, there are no dye couplers in the emulsion to record individual colors, simply the silver halides (plus sensitizers) reacting with photons. Recording black and white film with different color filters will only give you different tonal relationships, but not record any color information.
    As mentioned: not only will it work, it'll work well. A lot of colour work was done with b&w film. The idea of colour sep goes waaay back. In my own research on the topic, I quickly ran into James Clerk Maxwell; yes, the Maxwell of del dot B equals zero fame. That was around the 1860!!! Apparently Maxwell was the first to propose colour sep for capturing and displaying colour images. Nobody was thinking of multilayer colour film at the time, much less colour roll film or c41 or e6 or whatever.

    Doing IR colour sep will be easy. The interesting wrinkle is what colour channel you dump the IR info into; IR is, of course, invisible to us and doesn't have a colour. So it is a matter of choice. For spy photos you'd probably want the IR to be something other than red so that it stands out from that adjacent colour. But for more pleasing images I suspect that putting the IR image into the red or deep red channel of the final image will work. People can simply try and see for themselves... many creative possibilities here.

    Of course, the individual b&w images could also be developed as positives, they don't have to be developed as negs.

    Smart chemists like Ron could tell us how to make IR autochromes.

    As certain film options go off the market, we'll simply rediscover all the ingenious things that people used to do. It'll be fun, it really will.
    "Only dead fish follow the stream"

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