Meaning of FINDER in English
add. ·noun a slide ruled in squares, so as to assist in locating particular points in the field of vision.
2. finder ·noun one who, or that which, finds; specifically (astron.), a small telescope of low power and large field of view, attached to a larger telescope, for the purpose of finding an object more readily.
Webster English vocab. Английский словарь Webster. 2012