On 10 Mar 2005 at 12:53, John Francis wrote: > In theory it should make no difference - your camera can't tell > the difference between a white card under dim lighting and a > grey card under bright lighting.
Actually many camera/lens combos haven't sufficient latitude or low enough sensitivity to prevent over-exposure of a white card under sunlight so a grey reference may actually be preferable. > In practice there usually *is* a difference, although usually > ony of interest to gear heads. I've seen some colo(u)rimetric > results that suggest white cards are just a little more prone > to discolouration, so a gray card is a slightly better choice. > (The difference, though, is hardly noticeable - under 1%). Some popular grey cards have far worse colour accuracy and the better reference cards are designed to maintain their colour balance, they aren't cheap though. Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
