focal ratio (=focal-length ratio)

focal switch and focal shift

160120 focal plane array

35mm AF Focal Plane Cameras

35mm Multi Focal Points Lens Shutter Cameras

35mm NON-AF Focal Plane Cameras

35mm Single Focal Point Lens Shutter Cameras

adjusting focal length

air-defense groups for focal projects

amended focal length

anterior focal point

area infrared focal plane array

automatic focal length

back focal distance

back focal length

back focal plane

Best focal point

bi-focal

Bi-frequency focal ultrasound