Two kinds of gray (grey) cards?

Discussion in 'Beyond the Basics' started by burtharrris, Jun 21, 2007.

  1. burtharrris

    burtharrris TPF Noob!

    Joined:
    Jun 24, 2006
    Messages:
    183
    Likes Received:
    0
    Location:
    North Jersey
    I recently bought a digital photography book, and in the back it had a card with black, gray, and white on it. I read the chapter in the book about setting your photoshop Curves to the white black and gray colors, and I really like the results. It's a quick fix to make pictures much more lively.

    The point is, I have an old gray card from back in my slide and B&W film days. But it's gray color is much darker. When I balance the image to the (dark) gray card, it doesnt have the same look; it's flatter and darker lighting. Is the old dark gray card obsolete for color digital photography?

    Thanks!


    (By the way, I HIGHLY recommend the book for its image processing techniques, it goes past the basics: The Photoshop Book for Digital Photographers by Scott Kelby)
     
  2. Alpha

    Alpha Troll Extraordinaire

    Joined:
    Mar 15, 2005
    Messages:
    5,454
    Likes Received:
    41
    Location:
    San Francisco
    Can others edit my Photos:
    Photos NOT OK to edit
    Probably different % grays. Do the cards say the percentage?
     
  3. astrostu

    astrostu Guest

    Yeah ... gray/grey is simply not black nor white. Depending upon printing/dying accuracy in making the card, there's ((2^8)-3), ((2^16)-3), or ((2^32)-3) other shades in there that are still gray/grey. (-3 because -1 for sign, -1 for white, and -1 for black.)
     
  4. ann

    ann No longer a newbie, moving up!

    Joined:
    May 14, 2007
    Messages:
    4,263
    Likes Received:
    189
    Can others edit my Photos:
    Photos NOT OK to edit
    it could also be an aging factor.

    i just looked at the card you talking about and the midtone gray is the same tone as a gray card i have.
     
  5. burtharrris

    burtharrris TPF Noob!

    Joined:
    Jun 24, 2006
    Messages:
    183
    Likes Received:
    0
    Location:
    North Jersey
    That is very possible. The book is 4 years old and has been sitting on the shelf in my town library for awhile.
     
  6. Mike_E

    Mike_E No longer a newbie, moving up!

    Joined:
    Jan 26, 2007
    Messages:
    5,327
    Likes Received:
    264
    Location:
    The Upper West Side of Mississippi (you have no i
    Can others edit my Photos:
    Photos OK to edit
    Ansel Adams lobbied Kodak for 18% grey and got it. It seems that is what best suited the Zone System.

    Modern camera makers use a different- 12%- grey to calibrate their meters at the factory.

    Here is a link to Thom Hogan (quick google scan)

    http://www.bythom.com/graycards.htm

    I didn't read it beyond a quick scan, he may have better information on the wherefore's and the why's of it all.

    m
     
  7. jstuedle

    jstuedle No longer a newbie, moving up!

    Joined:
    Jun 30, 2005
    Messages:
    4,889
    Likes Received:
    14
    Location:
    S.E. Indiana
    Can others edit my Photos:
    Photos NOT OK to edit
    Another factor to look at is Kodak grays are made for film. You might find the film gray cards to have a slight color cast that will slide any WB off center. I use a card sold by Photo Vision and marketed by Ed Pierce. It has the W/G/B side that helps center exposure by histogram. I also shoot a frame of it any time I go into a different lighting condition. In post processing I can batch adjust for minor WB shifts for the whole shoot in those lighting conditions. The flip side is a handy reflector for shadow fill.
     

Share This Page