Results 1 to 10 of 10

Thread: exposure and white balance (grey card and white card)

  1. #1

    Default exposure and white balance (grey card and white card)

    Hi,

    As far as I have understood, white balance setting is due to the nature of light, as a white card is used for custom white balance setting.


    exposure is what the camera decides will be the best for a given photo. So if its a white curtain on sunlight and shot is for inside, it might think the curtains could be overexposed and try to reduce the exposure level, and the camera tries to make it 18% Grey and set its exposure.

    So how using a gray card is exposure fixed? like using a white card to set the white balance, how is the exposure set ?

  2. #2

    Default Re: exposure and white balance (grey card and white card)

    I mean is it such that the metering is locked/based to that 18% grey card, and after that refocus and shoot ?

  3. #3

    Default Re: exposure and white balance (grey card and white card)

    grey/white card has nothing to do with exposure.

    its for white balance.

    what is white balance? it has nothing to do with exposure. it just means your white/grey card will appear white/grey in your image.

    your white card can be blue if you shine blue light on it. right? then you can choose to either, let it remain blue, or use white balance to correct it to white.

    (or you can use white balance to correct away from white, make something white look yellow for instance)

  4. #4
    Moderator catchlights's Avatar
    Join Date
    Sep 2004
    Location
    Punggol, Singapore
    Posts
    21,902

    Default Re: exposure and white balance (grey card and white card)

    Shoot to Live, Live to Shoot
    www.benjaminloo.com | iStock portfolio

  5. #5
    Moderator catchlights's Avatar
    Join Date
    Sep 2004
    Location
    Punggol, Singapore
    Posts
    21,902

    Default Re: exposure and white balance (grey card and white card)

    Quote Originally Posted by IsenGrim View Post
    grey/white card has nothing to do with exposure.

    its for white balance.

    what is white balance? it has nothing to do with exposure. it just means your white/grey card will appear white/grey in your image.

    your white card can be blue if you shine blue light on it. right? then you can choose to either, let it remain blue, or use white balance to correct it to white.

    (or you can use white balance to correct away from white, make something white look yellow for instance)
    all along (since the heyday of film photography) photographers being using gray card for getting correct exposure.
    Shoot to Live, Live to Shoot
    www.benjaminloo.com | iStock portfolio

  6. #6

    Default Re: exposure and white balance (grey card and white card)

    Quote Originally Posted by catchlights View Post
    all along (since the heyday of film photography) photographers being using gray card for getting correct exposure.
    learnt something new today. i think its something i take for granted given the instant previews on digital cameras now adays.

  7. #7

    Default Re: exposure and white balance (grey card and white card)

    catchlights, Thank You.

  8. #8
    Moderator daredevil123's Avatar
    Join Date
    Oct 2005
    Location
    lil red dot
    Posts
    21,627
    Blog Entries
    1

    Default Re: exposure and white balance (grey card and white card)

    Quote Originally Posted by sglion View Post
    Hi,

    As far as I have understood, white balance setting is due to the nature of light, as a white card is used for custom white balance setting.


    exposure is what the camera decides will be the best for a given photo. So if its a white curtain on sunlight and shot is for inside, it might think the curtains could be overexposed and try to reduce the exposure level, and the camera tries to make it 18% Grey and set its exposure.

    So how using a gray card is exposure fixed? like using a white card to set the white balance, how is the exposure set ?
    Simple. Once you get the exposure metered on the 18% grey card, just use the metered values and set your camera to M mode.

  9. #9

    Default Re: exposure and white balance (grey card and white card)

    Quote Originally Posted by daredevil123 View Post
    Simple. Once you get the exposure metered on the 18% grey card, just use the metered values and set your camera to M mode.
    Can also do exposure lock; after metering you can lock the expousure without the need to go M mode. Check your camera manual for the AE-L button.

  10. #10

    Default Re: exposure and white balance (grey card and white card)

    Quote Originally Posted by catchlights View Post
    all along (since the heyday of film photography) photographers being using gray card for getting correct exposure.
    The 18% reflectance of the grey card represents the middle grey tone between black and white and is used as the standard for metering systems..

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
  •