GB1185875A - Method and apparatus for producing a Balanced Colour Print - Google Patents

Abstract

1,185,875. Photographic colour prints; colour comparison. HEATH CO. March 1, 1967, No.9791/67. Headings G2C and G2J. Balanced photographic colour prints are prepared from a colour negative using a printer (36) by (a) placing in the light path of the printer the negative and a filter (65) which compensates for the mask on the negative and for the colour defects of the sensitive material equipment, (b) displaying light passing through the filter and a selected area of the negative having a known colour, contiguous with a reference light, (c) matching the colour of the displayed lights by aligning a filter (112) with the filter (65), and (d) printing from the negative using filter (112). An apparatus, Fig. 4, for matching the lights comprises a housing 20 universally mounted on a base 24, a display deck 12 having a translucent area 14 surrounding a mirror area 16 and a filter pack holder 30. Light from the printer passes through a scan filter 32 in holder 30, and is reflected by the mirrored area 16 into the operator's eye. The translucent area 14 is illuminated by light from an incandescent source 92 which is rendered neutral white by a filter 70, the intensity of the light being reduced to that of area 16 by altering the axis of a polarizing filter 92 with respect to that of a polarizing filter 72 by means of a knob 34. The colours of areas 14 and 16 are then matched by aligning the filter (112) with scan filter 30. If the colour of the area of the negative to be matched is not neutral, the scan filter includes the complement of this colour so that neutral areas are compared.