Photographic printing apparatus

Abstract

The invention provides an apparatus for printing an image of a negative film on a photographic print paper. The apparatus is equipped with a zoom lens for changing a printing magnification rate and the zoom lens incorporates an adjustable diaphragm for changing an aperture size. A standard F-number for each of possible magnification rates is predetermined in view of actual printing result, and a resultant F-number is stored in a memory for each of possible magnification rates. In the apparatus provided a sensor, disposed on the optical axis of the zoom lens, for detecting the illuminance of a projected surface on the photographic print paper and CPU for controlling the adjustable diaphragm in response to the detected illuminance to determine an optimum aperture size to obtain the predetermined F-number for each of possible magnification rates. The optimum aperture size is stored in the memory for each of possible magnification rates.

Dependencies are inferred from the claim text.