field of view, <of a detector>
solid angle as "seen" by the detector (acceptance angle), e.g. of a radiometer or spectroradiometer, out of which the detector receives radiation
Note 1 to entry: The field of view should not be confused with the angular subtense of the apparent source,
Note 2 to entry: A plane angle is sometimes used to describe a circular symmetric solid angle field of view.
Note 3 to entry: The field of view is expressed in steradian (sr).
Note 4 to entry: This entry was numbered 17-429 in CIE S 017:2011.