Abstract Photomosaics can be useful tools for understanding and communicating geologic features expressed on outcrop faces. In order to utilize photomosaics properly, maximum resolution and minimum geometric distortion of the features is necessary. Maximum resolution is best obtained by using quality equipment and by attending to proper technique. In some cases increasing contrast will improve resolution; various methods can be utilized. Sufficient overlap of photographs in the construction of photomosaics will remove distortion in most situations. A common problem is perspective distortion, the convergence of vertical lines. This occurs when the film plane and outcrop face are not parallel and results in curved or "smiling" mosaics. When it is not feasible to obtain parallelism, several methods can be used to help correct this problem. In many situations fitting a 35-mm camera with a perspective control lens is the simplest and most economical strategy for reducing or eliminating the problem.