Air Force AMS - Aeronautical Material Specification AN - Air Force and Navy AND - Air Force-Navy Design ARP - Aircraft Recommended Practice AS - Aeronautical Standard Rad Radius ASD - Aeronautical Systems Division ASTM - American Society for Testing Materials CS or W - Cross-Section °C - Degrees Celsius Dia - Diameter fpm - Feet per minute; fpm = shaft die x rpm x 26 ID - Inside Diameter JIC - Joint Industry Conference on Hydraulic Standards for Industrial Equipment MIL - Military Specification MS - Military Standard OD - Outside Diameter psi - Pounds per square inch RMS - Root-mean-square; average value of surface roughness measured in microinches Spec - Specification USAF - United States Air Force
Autofocus - when the camera is pointed at an object, the lens will automatically focus on the subject This function (SLRs) can be activated usually by depressing the exposure button half way