Fabry lensA lens that forms an image of the telescope's primary mirror onto the photocathode of a photomultiplier tube and, in this way, serves as a key element of photometer. A mask, placed in front of it, isolates the object whose light intensity is to be measured. The use of such a lens was first proposed by the French physicist Charles Fabry. Related category OPTICS AND OPTICAL PHENOMENAAlso on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History |