How does the human visual system perceive colour/contrast under different light intensities?
Our visual system is tremendously good at adapting to the ambient lighting conditions. We automatically adapt our own ‘white point’ to the brightest white in our visual field. We also compensate for colour casts, so for example, you do not see everyone looking slightly green when you are sitting under a leafy tree on a sunny day. As a result of this, the lighting conditions where you work can have quite a noticeable effect on how images on a screen, or a print are perceived. To compare a print with an image on screen, they both need to be similar in brightness. You can get special viewing cabinets, with special adjustable lighting, designed for comparison work (they are not cheap – see the link above) Following on from this, one of the worst ways to compare a print with an image on screen, is to hold the print up next to the monitor. It is far better to have the print well lit, to one side of the monitor. You make a point of physically turning your head to look at the print – it take a