It would be easy to suppose that at least most human beings perceive the world in the same way, and that shapes, forms and colours were seen in the same way despite changes of environment. Photographers sometimes refer to "the real world" as though their eyes see what is "really there", and then strive to record the same scene with their camera. However, this is not the case. Perception is much more complex, and it is worth acquiring a basic understanding of some of the ways in which our own eyes can deceive us. While the perception of colour is of particular interest to photographers, there are numerous other phenomena, or optical illusions, which may influence the creation of excellent images.

Other articles on perception illustrate various effects which lead us to incorrect conclusions. We may see straight lines as curved, or parallel lines apparently converging. We may also be deceived in to thinking that shapes, forms or colours have characteristics which do not exist.Although we may be unable to prevent our eye and brain combination from perceiving the world in a particular manner, we can learn under what circumstances we are likely to be misled.