focal surface
Optics
noun
An imaginary curved (usually spherical) surface on which initially parallel rays come to a focus after passing through a lens or other optical system.
- A focal surface with no curvature is a focal plane..
Origin
Early 19th century; earliest use found in Transactions of the Royal Irish Academy.
- ultimate
- ultimate fighting
- Ultimate Frisbee
- ultimately
- ultima Thule
- ultimatum
- ultimo
- ultimobranchial
- ultimogeniture
- ultisol
- ulto
- ultra
- ultra-
- ultrabasic
- Ultrabook
- ultra-careful
- ultracentrifugal
- ultracentrifugation
- ultracentrifuge
- ultra-clean
- ultracold
- ultraconservatism
- ultraconservative
- ultracrepidarian
- ultracritical