White Balance & Gray Card

Discussion in 'Digital Photography' started by Dave Lotek, Aug 17, 2006.

  1. Dave Lotek

    Dave Lotek Guest

    What's the difference between using a gray card with film and using
    white balance with digital? Why not use a gray card with digital?
    Forgive me if I sound stupid but it's still a mystery to me. Thanks
    for your reply.

    Dave
     
    Dave Lotek, Aug 17, 2006
    #1
    1. Advertisements

  2. Dave Lotek

    acl Guest

    Hello,
    To do what? With film, I suppose you mean using a gray card to meter.
    You can still do this with digital, the TTL lightmeters are the same.
    You can also use it to white balance, which you can't do with film
    (except with filters or changing film, of course).
     
    acl, Aug 17, 2006
    #2
    1. Advertisements

  3. Dave Lotek

    gypsy3001 Guest

    You can still use a gray card with a digital camera . . . for metering.

    I don't understand how you would white balance with a gray card. You
    have to white balance with a white card . . . or a white sheet of
    paper. Or is there a recent change in technology that I am not aware
    of?

    Chieh
     
    gypsy3001, Aug 17, 2006
    #3
  4. Dave Lotek

    acl Guest

    Well, what you need is something that reflects all wavelengths equally
    (roughly). There is no difference, in this context, between a white
    card and a gray one. For example, spot meter off a white card and
    expose as the camera suggests. You'll get gray. The point here is that
    the perceived colour of an object doesn't change if the reflectivity
    for all wavelengths is changed by the same factor.
     
    acl, Aug 17, 2006
    #4
  5. Dave Lotek

    Ken Weitzel Guest

    Hi...

    One more way of saying much the same thing, but may
    make it a little more understandable...

    In the white balance context - white doesn't mean white,
    but rather refers to an absence of color. :)

    Take care.

    Ken
     
    Ken Weitzel, Aug 17, 2006
    #5
  6. Dave Lotek

    Jay Beckman Guest

    You can white balance with a black card if you want ...

    Like another poster mentions, you want an absence of color.

    Jay
     
    Jay Beckman, Aug 17, 2006
    #6
  7. Dave Lotek

    acl Guest

    Of course, if it really is black, it'll take you an infinite amount of
    time...
     
    acl, Aug 17, 2006
    #7
  8. Dave Lotek

    Bill Funk Guest


    I think you're confusing the purpose of the gray card, which is used
    to help set exposure, with white balance.
     
    Bill Funk, Aug 17, 2006
    #8
  9. Dave Lotek

    acl Guest

    So, do you disagree with the following statement: "One can set white
    balance by using a gray card"?
     
    acl, Aug 17, 2006
    #9
  10. Dave Lotek

    Ken Weitzel Guest

    Hi...

    Oddly worded, so just in case... :)

    One CAN set white balance using a gray card.

    If anyone is skeptical, google gray card, note the
    number of responses that come up referring to the use
    we're speaking about.

    Try it again with white card, see what you find, again
    paying attention to the context.

    Take care.

    Ken
     
    Ken Weitzel, Aug 17, 2006
    #10
  11. Dave Lotek

    Mark Roberts Guest

    Here's an article on the subject:
    http://www.outbackphoto.com/workflow/wf_65/essay.html

    Short answer is that you can use a gray card for white balance because
    your camera can't tell the difference between a white card in low
    light and a gray card in bright light. As long as your gray card
    really is a true *neutral* gray (and some cheap ones aren't) you'll be
    OK.

    Personally I use white mat board scraps. You'll find that art stores
    have a huge number of different shades of "white". Experiment and
    you'll be able to come up with "white cards" that produce all kinds of
    variations from warm to cool. Just be sure to keep notes - including
    the manufacturer and catalog number of mat board samples that produce
    color balances you like.
     
    Mark Roberts, Aug 17, 2006
    #11
  12. Dave Lotek

    Bill Funk Guest

    Are you looking for trouble?
    Did I say that?
    If you want to set white balance with a gray card, fire away.
     
    Bill Funk, Aug 17, 2006
    #12
  13. That statement is actually true for some cameras, because I do have an older
    point-and-shoot digital camera that uses gray to set manual white balance.

    From the Nikon Coolpix 2100 manual, page 61:

    [begin quoted text]
    Preset white balance is used when shooting under mixed lighting or to
    compensate for light sources with a strong color cast (for example, to make
    pictures taken under a lamp with a red shade look as through they had been
    taken under white light).

    ....

    To measure a new value for white balance, place a gray object, such as a
    piece of cardboard, under the lighting that will be used in the final
    picture. Frame this object so that it fills the square in the center of the
    menu shown above. Highlight Measure and press the multi selector to the
    right to measure a new value for white balance (shutter will be released and
    camera will return to original zoom position, but no picture will be
    recorded).
    [end quoted text]
     
    Daniel W. Rouse Jr., Aug 17, 2006
    #13
  14. Dave Lotek

    no_name Guest

    Why not indeed? I do it.

    White balance in digital is like chosing the right film i.e. daylight
    film or tungsten or putting a magenta correcting filter on the lens when
    you're shooting under flourescent lights.

    Grey card is useful in setting exposure, i.e. getting neutral midtone.
    They're not mutually exclusive.

    I usually carry a Macbeth color checker and a triple card that has
    white/gray/black. Shoot the first frame with the color checker and
    triple card & you can batch process your color correction for the rest
    of anything you shoot under the same light.
     
    no_name, Aug 17, 2006
    #14
  15. Dave Lotek

    no_name Guest

    In the white balance context - white means the color temperature of
    white under specific types of light: 3200k for tungsten, 5400k for
    daylight, 6000k for flash, 10,000k for skylight ...
     
    no_name, Aug 17, 2006
    #15
  16. Dave Lotek

    bruin70 Guest

    when you WB, you're only looking for NEUTRALITY in color. a grey card
    is neutral, as is a white card.
     
    bruin70, Aug 18, 2006
    #16
  17. Dave Lotek

    bruin70 Guest

    i AGREE with that statement....one CAN set wb with a grey card. a
    photographer's grey card is purposely neutral in color.

    and i will go even further,,,,A GREY CARD IS BETTER THAN A WHITE CARD
    FOR WB, because white will reflect more ambient color than grey.
     
    bruin70, Aug 18, 2006
    #17
  18. Dave Lotek

    ASAAR Guest

    If the light source responsible for the ambient reflections is
    also the source illuminating the card, the ratio of ambient color
    reflecting from the card to the amount of the source's light
    reflecting off the card should be roughly the same, whether a gray
    or white card is used. But another solution that would eliminate
    much of the ambient color reflecting from the card would be to set
    the white balance after putting an ND filter on the lens. <g>
     
    ASAAR, Aug 18, 2006
    #18
  19. White balance can *always* be set with a gray card, just as easily as with
    a white card.
     
    Floyd L. Davidson, Aug 18, 2006
    #19
  20. Dave Lotek

    acl Guest


    Trouble? I think you need to get a grip on reality.
     
    acl, Aug 18, 2006
    #20
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.