Focal length? F-stops? Shutter speed? X-sync? ISO? WTFOMGROFLBBQ?!

Also see

Derek's Nikon F4s - fully disassembled

01 - Simple lens focal length

02 - Camera lens focal length

03 - Different focal lengths

02b - Nikon F4 focal plane

04 - Focal length ray angles

05 - Angles of view

06 - Fields of view

Aperture diaphragm blades

50mm f/1.8 lens front 50mm f/16 lens front

Depth of field demo - f/1.8 Depth of field demo - f/22

Aperture and focal length

Canon A540 lens

Aperture ring

Shutter speed dial