• 04-03-2006, 07:25 AM
    shutterman
    Attention GretagMacbeth Users - HELP!
    Ok, so I got one of their color checkers - 24 squares of scientifically tested color.

    Now the question is - how do I use it in my workflow. The directions were a little fuzzy there.

    Here is what I am doing.

    Before a studio shot I will take a test shot with the color checker in the frame under the same conditions I will use for the real shots.

    Now when I transfer the images to my computer how do I adjust the colors to match the color checker?

    Here is what I am using - D200, studio lighting, CS2. Monitor is calibrated with the Spyder.

    Any ideas would be a big help!

    Thanks,
    Wes
  • 04-03-2006, 09:01 AM
    another view
    Re: Attention GretagMacbeth Users - HELP!
    I've never used one, but that's what I'd do. I would pick the white, middle grey and black on the card with the eyedropper in Photoshop with that shot, then convert all of the images together based on those settings.

    Good to hear that you're calibrating your monitor. Without it, you really wouldn't get much benefit from it other than pure luck!
  • 04-03-2006, 05:31 PM
    Peter_AUS
    Re: Attention GretagMacbeth Users - HELP!
    shutterman you need to zoom in to fill the viewfinder with the colour checker under the same lighting conditions then when you take the captures into your program, you set the white balance using the 18% grey scale patch. They you select the other images and apply the change to those images.

    That is the theory of how to do it. Problem is I don't know exactly how Photoshop does it as One I don't use Photoshop to edit my RAW images I use Capture One, Two I don't have a Nikon so can't guide you on that one.

    The above principal that I described is the process.
  • 04-04-2006, 06:22 AM
    shutterman
    thanks Peter and AV
    I did some testing last night. I started by using the dropper to set the 18% gray point and then used the sliders in the levels tool to get the rest of the colors as close as I could. I then saved this setting and applied it to the rest of the images and they look pretty good. The hard part is the white is not 100% white and the black is not 100% black!

    They have some techs that I can call and walk me through it in case I am missing something obvious but you put me on the right track (I think :) )

    thanks,
    Wes
  • 04-04-2006, 01:35 PM
    racingpinarello
    Re: Attention GretagMacbeth Users - HELP!
    Hi,

    What I do is to have the color checker near the subject and take a test photo. Make sure that the grey square reads grey (125,125,125) otherwise you are under/over exposed. Adjust the camera settings until that square reads grey.

    Using the droppers, I chose the white, gray, and black squares and then save that curve. Then I apply that curve to the rest of the images in that batch.

    Another thing I do is to check the numbers. Using three color samples on white, grey, and black I then try to adust the curve so that white is really white, and so on.

    The third thing that I do is use the initial test image. If I have red subject it should be fairly close in numbers to the red square.

    I used the Greytag Macbeth color checker Eye-One system, and I use the color chart to test exposure for film/camera combinations and color balance for digital.

    Loren
  • 04-04-2006, 08:40 PM
    shutterman
    Re: Attention GretagMacbeth Users - HELP!
    Loren,

    Thanks. I used this process tonight and it works like a charm! Thanks again for taking the time.

    Wes