GB483820A - Improvements in or relating to cameras - Google Patents

Abstract

483,820. Lens mounts ; colour photography. HILLMAN, A. G., and JOHNSON, G. H. Sept. 9, 1936, No. 24614. [Classes 97 (i), 98 (i), and 98 (ii)] A screw-operated focusing mount for a kinematographic or photographic camera of the kind in which the screw surfaces encircle the objective comprises a plurality of objectives in a screw threaded mount which is axially displaceable by a co-operating screw-member for simultaneously focusing the objectives and fine adjusting means for partially rotating the mount about the axis of its screw surface so as to turn one or more of the objectives bodily about such axis for controlling the arrangement of the images cast by the objectives on the image-receiving surface, the means serving to restrain the mount against rotation whilst it is being moved axially during focusing. As shown, the mount 4, carrying three lenses 1, 2, 3, has an external thread 5 engaged by a rotatable axially restrained nut 6. Projecting from the mount is a spring arm 7 carrying a pin 8 engaged by screws 10, 11, adjustment of which rotates the mount to bring the centres of the lenses 1 and 2, fixed in the mount, into vertical relationship. The lens 3 is mounted in a laterally elongated aperture, and by loosening the holding screws 15 and slackening one of the screws 10, 11, the mount can be rotated by the arm 7. A stop against the lens 3 causes the lens to move laterally on rotation of the mount, and permits its adjustment into vertical alignment with the other lenses. The elasticity of the arm 7 permits axial movement of the mount for focusing. Alternatively a slide-guided rigid arm 7 may be used. The nut 6 may be provided with a pointer 22 co-operating with a scale. The adjustment of the lens 3 may be effected by screw means. The lenses may be independently focused by the use of opposing screws allowing the lenses to be moved axially in either direction. A camera incorporating the lens mount may be used to produce a series of colour component negatives on a single film, and from this film a positive for projection through colour filters can be printed, or colour component matrix films for imbibition printing may be printed therefrom. The camera may also be used to produce black and white films. Specification 483,817 is referred to.