
My question to the learned members is this - is there a grey card available in Oz that has the following:
white - reflectance 90.7
black - reflectance 3.6
then patches with the following reflectance: 25.5, 22.7, 20.2, 18 (mid grey), 16, 14.3 and finally 12.7.
Thanks for any help on this one