Increasing device with a single light source for the implementation of the image maes strength main exposure of the seeds and a degree of supplemental exposure sprung aen

摘要

1,182,598. Photographic enlargers. W.H. HOWSON Ltd. March 3, 1967 [March 9, 1966], No.10327/66. Headings G2A and G2C. In an enlarger, the main exposure (i.e. the exposure of the light-sensitive material to an image focused thereon of the object being photographed) and the flash exposure (i.e. an overall non-focused exposure to control the contrast) are carried out simultaneously from the same light source. As shown, light from a source 1 passes through a negative or transparency in a carrier 5, and is focused by the objective 14 on to lightsensitive material on an easel 15. The negative carrier 5 Fig. 2 (not shown) consists of a transparent plate having an outer opaque border (6) and an inner transparent border (7) surrounding the central area occupied by the transparency (9). Below this is an adjustable mask 12 Fig.3 (not shown), comprising a central area defined by four movable strips (10). Below mask 12, mirror pairs 17 intercept light coming through the clear border (7), and reflect it towards the objective 14, after which it passes to diffusion strips 16. This light A, ASP1/SP carries no image, and surrounds the central image-carrying light B, BSP1/SP. Thus the easel, besides receiving the focused image, is also illuminated evenly by the non-focused light A, ASP1/SP, ASP11/SP.