A&P How can a whibal card work

Discussion in 'Lifestyle' started by Pineapple Devil, Dec 2, 2006.

  1. Pineapple Devil

    Pineapple Devil beat it!

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    if the lighting tints the card? say that there are lightbulbs putting out a yellow tint on the white portion of the card, what good is the card if its going to keep whites tinted?

    am i understanding it correctly?
     
  2. Jonny Chimpo

    Jonny Chimpo OT Supporter

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    A whibal card is a known value - 18% grey - and that known value is stored in photoshop, so when you set your grey balance in the software it subtracts the color delta between the known (stored) value and the value read on the whibal patch.

    Although, it sounds like you are talking about a white balance card which basically works the same way, but the camera subtracts the color delta between pure white and the measured value when you set a custom white balance.

    That color delta is then saved and used to correct all colors in the photo.
     
  3. Dwight Schrute

    Dwight Schrute New Member

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    That's not how it works. Say for example you have a halogen light illuminating the card. The card will have a yellowish tint. If you do a custom white balance measurement on the card, the camera knows that whatever it is metering is supposed to be white, and when it isn't, it compensates for the difference.
     
  4. Schproda

    Schproda New Member

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    You're metering on a neutral color. I shot a show last night where the singer had a gray shirt on. If a warm tint is of a concern use a custom white balance before you shoot and do a test shot or two first. Or just shoot and when you're done, change the temperature of your photos when you're post processing them.
     
  5. Dwight Schrute

    Dwight Schrute New Member

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    And make sure you shoot RAW, or this won't work (well).
     
  6. Schproda

    Schproda New Member

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    I don't know first hand, but Halogen isn't tungsten and doesn't show yellow. If it does, see above.
     
  7. Schproda

    Schproda New Member

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    Thank ya!
     
  8. Jonny Chimpo

    Jonny Chimpo OT Supporter

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    I'm hoping you aren't referring to my post. we said the same thing. :wiggle:

    :nono: Just learn to set your camera correctly in the first place and don't rely on post production software to fix your mistakes.
     
  9. Dwight Schrute

    Dwight Schrute New Member

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    Tungsten is very cool, i.e. blue. Halogen is warm, i.e. yellow.
     
  10. Dwight Schrute

    Dwight Schrute New Member

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    :rolleyes: I was responding to the previous poster's point that you can fix the white balance in post.

    And there is nothing wrong with doing that. You can't always get the perfect white balance in the field. And many times you don't have time to whip our your grey card and meter it.
     
  11. Pineapple Devil

    Pineapple Devil beat it!

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    is there a way to make one?
     
  12. Schproda

    Schproda New Member

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    Since when it tungsten not yellow? :)

    • 1700 K: Light of matches
    • 1850K : a candle
    • 2800 K: tungsten lamp (ordinary household bulb whatever its power)¨
    • 3350K : studio "CP" light
    • 3400 K: studio lamps, photofloods,
    • 5000 K: Daylight°
    • 5500 K: average daylight, electronic flash (can vary between manufacturers)
    • 5770 K: effective sun temperature
    • 6420 K: Xenon arc lamp
    • 6500 K: Daylight°
    • 9300 K: TV screen (analog)
    • 28000 - 30000 K: a lightning bolt [1]
    [​IMG]
     
    Last edited: Dec 2, 2006
  13. Dwight Schrute

    Dwight Schrute New Member

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    No sorry, I was referring to the OP. You posted while I was typing my response. :)
     
  14. Blair

    Blair New Member

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  15. Tedrzz

    Tedrzz New Member

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    If you are wearing a white shirt in incandescent lighting, it will be yellowish. But if you set a whitebalance off of it, you basically telling your camera everything that is that certain color is white, instead of yellowish.

    makes perfect sense to me..
     

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