A Alternative Processes 25 The major photographic processes are the common film and digital imaging methods in use today ­ colour negative and reversal, black-and-white film and digital photography ­ many involving imaging based on silver halide chemistry. The description `alternative processes' covers historical or commercially abandoned ways of creating imagery used by artists and photographers or hobbyists today. Many involve chemical processes other than silver halide. Some, like Vandyke brown, use the