Primarys

Discussion in 'Beyond the Basics' started by Protean, Jul 3, 2006.

  1. Protean

    Protean TPF Noob!

    Joined:
    Jun 19, 2006
    Messages:
    73
    Likes Received:
    0
    ok, so with light the primary colors are rgb right? not ryb like with paints...

    so what are all the color combos for teh secondary colors then i.e.

    r+g=?
    r+b=?
    g+b=?

    iow. what does the color wheel for light look like?
     
  2. Torus34

    Torus34 No longer a newbie, moving up!

    Joined:
    Jan 26, 2006
    Messages:
    2,117
    Likes Received:
    37
    Location:
    Tottenville, Staten Island, NYC USA
    Can others edit my Photos:
    Photos OK to edit
    Oh, boy! Have you ever opened a can of worms!

    When discussing light, you have to be a bit careful of the context.

    The three colors for color slides and for color negative film are different.

    If you're talking about the color temperature of the light, you're involved in the infrared, red, orange, yellow, white, blue sequence of black body radiation.

    If you're enlarging color negative film, the three important colors are yellow, cyan and magenta.

    If you're using a color head enlarger with variable contrast paper, yellow and magenta are the colors which matter.

    If you are controlling gray density of specific objects in a B&W image, you'll get into color filters covering the full rainbow range.

    And infrared film? That's a story in itself.
     
  3. markc

    markc TPF Noob!

    Joined:
    Mar 8, 2004
    Messages:
    4,237
    Likes Received:
    6
    Location:
    Rochester, NY Velocity: Unknown
    Can others edit my Photos:
    Photos NOT OK to edit
  4. Protean

    Protean TPF Noob!

    Joined:
    Jun 19, 2006
    Messages:
    73
    Likes Received:
    0
    that link help a lot, thanks.

    and wow, glad i don't do any film stuff yet lol
     
  5. Tiberius

    Tiberius TPF Noob!

    Joined:
    Jun 19, 2006
    Messages:
    328
    Likes Received:
    0
    Location:
    Michigan, USA
    Light is based on the adding of colors - Red, Green, Blue. When you add red and green you get yellow, green and blue is cyan, etc. Painting pigments are based on the subraction of colors - Red Paint absorbs green and blue light, etc. With pigments, mixing red and green will give you a hideous brown color. The addition/subtraction confusion is what causes the different results.
     

Share This Page