- #1
WaltLankor
- 9
- 0
I'm puzzled.
In an authoritative metrology text I read.
"Focus detection instruments cannot be used to measure 'opaque' surfaces"
as they require a finite level of reflected light to function.
Non transmittance being (to my understanding) the key definition of "opaque", I looked up the meaning of opaque in various places. A significant number of references give non transmittance and reflectance as the definition of an "opaque" surface.
Any definitive comments on this would be appreciated.
Thanks
In an authoritative metrology text I read.
"Focus detection instruments cannot be used to measure 'opaque' surfaces"
as they require a finite level of reflected light to function.
Non transmittance being (to my understanding) the key definition of "opaque", I looked up the meaning of opaque in various places. A significant number of references give non transmittance and reflectance as the definition of an "opaque" surface.
Any definitive comments on this would be appreciated.
Thanks