One of the most important things to do before looking at the various images contained in this website is to ensure your monitor is setup correctly.
Using the following images set brightness and contrast as follows:
Using the gray scale wedge below you should be able to easily see each of the graded steps. The first step should be 0 black. The usual setup method is to set the monitor's contrast to maximum or near maximum and then adjust the brightness control until the black steps can just be distinguished from each other.
Using the following image you should be able to see a difference in shade between blocks X, Y and Z and also, preferably A, B and C. For best viewing results there should be a roughly equal step between each band.
Reproduced with kind permission of Steve Shaw - Light Illusion.