The use of liquid crystal displays in combination with projection is not new. However, this type of display is becoming even more prevalent than it has been in the past. A variety of such displays are currently available for commercial or even consumer use. In this paper the authors review a number of liquid crystal devices, also known as light valves, developed specifically for use in projection systems. These include not only analog-addressed devices such as the photoactivated liquid crystal light valve, but matrix-addressed displays as well.