focus Comparison Table

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focus comparison table

Subject has definition

coudé focus A stationary focal point in an equatorial mounted telescope obtained by an arrangement of small auxiliary mirrors in the converging beam which eventually directs the light down the hollow polar axle of the telescope.

prime focus The focal point of the large primary reflecting mirror in astronomical telescopes when the light source is extremely distant. This focus actually falls at a point just within the upper structure of the telescope itself and is therefore accessible to CCD cameras and other instruments; it provides a large field of view.

Subject	has definition
coudé focus	A stationary focal point in an equatorial mounted telescope obtained by an arrangement of small auxiliary mirrors in the converging beam which eventually directs the light down the hollow polar axle of the telescope.
prime focus	The focal point of the large primary reflecting mirror in astronomical telescopes when the light source is extremely distant. This focus actually falls at a point just within the upper structure of the telescope itself and is therefore accessible to CCD cameras and other instruments; it provides a large field of view.

Next optical device: wavefront modifier Up: optical device Previous optical device: detector