flus - free
- focusing arrangement
- focusing assembly of cathode
- focusing camera
- focusing cap
- focusing condition
- focusing effervescive
- focusing force
- focusing hood
- focusing method
- focusing monochromator
- focusing reflector
- focusing Soller slits system
- focusing spectrograph
- focusing tube
- Foerster probe
- fog
- fog density of film
- fog quenching
- fog room
- fog test