Results 1 to 20 of 20

Thread: White Balance Misconception

  1. #1

    Default White Balance Misconception

    Using a white card to manually adjust white balance, it is possible to achieve a picture without colour casts. But I've heard people saying that white remains white in whichever colour temperatures/lighting. Is it truely so? I've been thinking about it and realized that a white card placed under red light would be red. So the white does not remain white?

  2. #2
    Member
    Join Date
    Oct 2002
    Location
    Singapore
    Posts
    369

    Default Re: White Balance Misconception

    Quote Originally Posted by megascriler
    Using a white card to manually adjust white balance, it is possible to achieve a picture without colour casts. But I've heard people saying that white remains white in whichever colour temperatures/lighting. Is it truely so? I've been thinking about it and realized that a white card placed under red light would be red. So the white does not remain white?

    White is made up of the 3 primary colours, red blue green. (equal amts)
    as long as there is a reasonable amount of red, reasonable amt of green and reasonable amt of green. our eyes tell us that it is white (even though they are not the same).

    The camera is able to pick up the slight differences hence we have to tell the camera that the "colour" object that we are seeing is white. (camera automatically compensates the difference between the red, blue and green) so that white remains white.

    our eyes are Not able to detect slight differences unless we put them next to another sample we will not be able to tell the difference.

    As to your question about the red light, there is no other colours except red so the card will not be white.
    Last edited by Hobbes234; 27th August 2006 at 12:35 PM.

  3. #3
    Senior Member
    Join Date
    Jul 2003
    Location
    Tampines, Singapore.
    Posts
    1,899

    Default Re: White Balance Misconception

    isn't WB calibration done with an 18% grey card?

  4. #4
    Member
    Join Date
    Dec 2005
    Location
    AMK
    Posts
    915

    Default Re: White Balance Misconception

    Quote Originally Posted by hwchoy
    isn't WB calibration done with an 18% grey card?
    i tot dis is for correct exposure of bright and dark places..

  5. #5
    Member
    Join Date
    Oct 2002
    Location
    Singapore
    Posts
    369

    Default Re: White Balance Misconception

    Quote Originally Posted by VR2
    i tot dis is for correct exposure of bright and dark places..
    yes. the grey card tells u the correct exposure at a certain lighting condition.

  6. #6
    Senior Member
    Join Date
    Dec 2003
    Location
    Tampines
    Posts
    3,287

    Default Re: White Balance Misconception

    I don't think there is a misconception here but just a misunderstanding.

  7. #7

    Default Re: White Balance Misconception

    Has anybody actually cheated the camera?
    telling the camera that blue is white, yellow is white, red is white, etc.
    The effects are actualy similiar to adding a blue or yellow or red filter?
    I tried once to cheat the camera light blue is white,
    and while shooting an ang moh's kid, the skin tone appears to be very nice...

  8. #8
    Senior Member
    Join Date
    Jan 2006
    Location
    West Legion
    Posts
    7,751

    Default Re: White Balance Misconception

    Quote Originally Posted by scaredcloud
    Has anybody actually cheated the camera?
    telling the camera that blue is white, yellow is white, red is white, etc.
    The effects are actualy similiar to adding a blue or yellow or red filter?
    I tried once to cheat the camera light blue is white,
    and while shooting an ang moh's kid, the skin tone appears to be very nice...
    im pretty sure that everyone that does IR photography cheated their camera

  9. #9
    Moderator catchlights's Avatar
    Join Date
    Sep 2004
    Location
    Punggol, Singapore
    Posts
    21,902

    Default Re: White Balance Misconception

    grey card is able to use for white balance setting, since it is neutral in tone.
    Shoot to Live, Live to Shoot
    www.benjaminloo.com | iStock portfolio

  10. #10
    Senior Member
    Join Date
    Jul 2003
    Location
    Tampines, Singapore.
    Posts
    1,899

    Default Re: White Balance Misconception

    catchlights, is there a difference in doing custom WB (I am using 20D) using a 18% gray card or a white card?

  11. #11
    Member
    Join Date
    Apr 2004
    Location
    Singapore
    Posts
    77

    Default Re: White Balance Misconception

    The idea of WB on grey or white card is similar. If you use an 18% grey, you know its accurate cos you paid a fair bit of $, so it better be neutral (unless you mistreat it). For white, there are 2 things:
    1. Are you sure your white is white? Your A4 paper might be carrying a slight warm or cool tone... but if you're in a rush, it's a quick fix. Generally it works okay unless you want dead accurate WB.
    2. Are you sure your camera isn't overexposing the white? If your white paper is clipped off the histogram, you aren't going to get any colour.

  12. #12
    Senior Member
    Join Date
    Jul 2003
    Location
    Tampines, Singapore.
    Posts
    1,899

    Default Re: White Balance Misconception

    ok, specifically on canon DSLR, when you select an image for custom wb, it should be the image of a gray card yes?

  13. #13
    Senior Member +evenstar's Avatar
    Join Date
    Jan 2004
    Location
    Singapore / United Kingdom
    Posts
    5,655

    Default Re: White Balance Misconception

    Quote Originally Posted by hwchoy
    ok, specifically on canon DSLR, when you select an image for custom wb, it should be the image of a gray card yes?
    it can be a white card...cos when you shoot an image, the auto exposure will still underexpose the shot to make the white a grey, unless you +1 or +2 stops...
    eat. drink. shoot

  14. #14

    Default Re: White Balance Misconception

    But grey cards are better than white ones right? Since white does not remain white in drastic coloured lighting but grey does since it is neutral?

    And thank you to everyone for answering my previous misunderstanding.

  15. #15
    Senior Member +evenstar's Avatar
    Join Date
    Jan 2004
    Location
    Singapore / United Kingdom
    Posts
    5,655

    Default Re: White Balance Misconception

    i supppose so...but i ususally just use my gigantic white bounce card for take a shot for custom WB..
    eat. drink. shoot

  16. #16

    Default Re: White Balance Misconception

    Quote Originally Posted by megascriler
    Using a white card to manually adjust white balance, it is possible to achieve a picture without colour casts. But I've heard people saying that white remains white in whichever colour temperatures/lighting. Is it truely so? I've been thinking about it and realized that a white card placed under red light would be red. So the white does not remain white?

    Interesting.. I wonder what will happen to the photo if we place a white card under red light and set custom white balance using that?

  17. #17
    Member
    Join Date
    Dec 2005
    Location
    AMK
    Posts
    915

    Default Re: White Balance Misconception

    Quote Originally Posted by zeith
    Interesting.. I wonder what will happen to the photo if we place a white card under red light and set custom white balance using that?
    try out and let us know..

  18. #18
    Moderator catchlights's Avatar
    Join Date
    Sep 2004
    Location
    Punggol, Singapore
    Posts
    21,902

    Default Re: White Balance Misconception

    Quote Originally Posted by hwchoy
    catchlights, is there a difference in doing custom WB (I am using 20D) using a 18% gray card or a white card?
    It is easy to find a white object, a white paper or card to do a custom WB, and the cost is almost zero, however, a gray card will be better, since it calibrated to be neutral, but a gray card is costly, and not mean for casual shooters, so most camera manual do not stress on using a gray card for custom WB.

    and alexj has given a detail explaination about using a white card.

    Hope these help.
    Shoot to Live, Live to Shoot
    www.benjaminloo.com | iStock portfolio

  19. #19

    Default Re: White Balance Misconception

    OK thanks everyone!

  20. #20
    Senior Member
    Join Date
    Jul 2003
    Location
    Tampines, Singapore.
    Posts
    1,899

    Default Re: White Balance Misconception

    Quote Originally Posted by catchlights
    It is easy to find a white object, a white paper or card to do a custom WB, and the cost is almost zero, however, a gray card will be better, since it calibrated to be neutral, but a gray card is costly, and not mean for casual shooters, so most camera manual do not stress on using a gray card for custom WB.

    and alexj has given a detail explaination about using a white card.

    Hope these help.
    thanx I use a gray card normally but I had to use a laminted white card when customising WB for shooting through water!

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •