We have all seen them – pictures with white backgrounds. White is probably the most common color (or lack thereof) for a photo background.
The most obvious reason for this is that white backgrounds are the most commonly occurring for pages of text. Having the image background the same color as the printed page or screen makes integration between text and images easy. It is also a good starting point for extractions when one wants to have different background color options.
A white background helps the colors to “pop” without competing colors in the background.
Sometimes the desire is just to have an image of the subject without the distraction of a bounding rectangle.
Producing an image with a “clean white” background is not the same as just shooting an image against a white background because without particular care, the “white” of the background will not match the white of the page and you will still have a bounding rectangle as can be seen from the two images below:
Particular care must be taken to light both the subject and background independently as both subject and background have different lighting requirements. A white backdrop does not guarantee that the background will come out looking white in the final image as can be seen by these images in which the subject was lit identically. The difference being that one had light on the background and the other did not:
Even a lily-white background will come out looking gray if there is not enough light hitting it. Additionally if too much light hits it, the result is “ghosting” with the light coming from behind affecting the subject:
This may be a desirable look for some kinds of work, but where it isn’t, special care needs to be taken to ensure there is enough light to ensure the background comes out looking white, but not so much that it reflects off the background and affects the look of subject. The intensity of the light and distance to the background must be just right. When the subject is against a white backdrop, problems can arise with backdrop texture and shadows:
Natural (window or outdoor) light used by itself, is almost never going to satisfactorily achieve the desired (clean white) look. This kind of work will be accomplished on a consistent basis by a photographer who is competent in lighting.
For the reasons stated above this is a very useful look for both people and products in printed materials and on screen, for publication and for advertising. While it is possible to use different kinds of backgrounds and extract the subject using photo manipulation tools, this tends to be an inefficient approach and can be especially unwieldy for large numbers of images or where quick turnaround is a necessity.