color filters, but gels instead

Discussion in 'Color: Film, Paper, and Chemistry' started by jnanian, Sep 11, 2013.

  1. jnanian

    jnanian Advertiser Advertiser

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    i am trying to use color gels to use as filters.
    it probably doesn't make much sense ..
    but i am looking for a 25 red, 58 green and 47 blue but in light gels instead
    does anyone know if light gels (rosco ? ) comes the same way as lens filters do
    or will i have to experiment a little to see if the filters i am trying to make on the cheep
    will be the same ... or will the light shop i go to know exactly what i need ...?
    why am i doing this ?
    i have some lenses that have a huge front element that i want to make color separation negatives with
    but unfortunately it is expensive or nearly impossible for me to get a set of color filters that are 3 or 4 inches across .. so
    i am trying a work around.

    any other suggestions would be appreciated too ..

    john
     
  2. Mike Wilde

    Mike Wilde Member

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    Look up the transmission graphs for the gels you want on the Kodak side, then compare them to the technical curves for the Rosco stuff.

    While not optically perfect, the theatrical gel at about $6 per 20x24 sheet is a lot more affordable to experiment with.

    I do have a set of wratten separation filters as you are looking for, but alas in only the 2x2" size.

    The other option is if you can get to the insde of the lens, ie if the lens is fitted to a shutter, put the filters inside the lens.

    Lock the camera down, swap the lens board out between shots, and screw and unscrew to change filters on the inside of thel ens.

    More of a PIA, but likely a lot less $$$ to try this approach. I would only try this for studio still lifes, or copy stand work but that is usally the case for making separation negatives, now isn't it.
     
  3. jeffreyg

    jeffreyg Subscriber

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    Anchor Optics division of Edmund Optics has a roscolux 3"x5" filter color book of 100 filters with a spectral chart for each color for approximately $40. That might be what you are looking for.

    http://www.jeffreyglasser.com/
     
  4. jnanian

    jnanian Advertiser Advertiser

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    thanks guys

    i think after looking at the wratten &c colors and charts i am just going to get the DARK gels in green red and blue
    im not planning on doing "part 2 " the old tried and true way but using another method i can't really talk about here,

    thanks again for your suggestions !

    john
     
  5. Mainecoonmaniac

    Mainecoonmaniac Subscriber

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    Rosco gels are not the greatest quality for lenses. There are tons of Cokin knockoff resin filters on Ebay from China that's decent quality.