Focusing Device
Jump to navigation
Jump to search
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.
2-4-050
Alternative term: Focuser (G.B.)
An optical device used for focusing (2-2-155), for example, a short telescope with cross-wire, fixed to the frame of the optic.
Note: In France and Germany, the type of focusing device mainly used projects, by means of lenses and prisms, an image of the luminous element of the light source on a screen fitted with a cross-wire and usually also with concentric rings.
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)