GB1313895A - Motion picture camera mounts - Google Patents

Abstract

1313895 Camera mountings RANK ORGANISATION Ltd 28 April 1971 [6 July 1970] 32697/70 Heading G2A In an arrangement in which a camera photographs an image projected on to a reflexive screen together with a subject placed between camera and screen, by means including a semitransparent mirror, the mirror is mounted on a carriage such that it moves with the camera as the latter executes a panning movement about a vertical axis. As shown, a main bar 1 is pivotally mounted at one end on a post 2 on which the camera itself (not shown) is also mounted so that it can be pivoted in a panning movement about the post. On either side of the bar 1 are mounted segment-shaped members 3, 4 having respective slots 5, 6, the slots providing a continous straight guideway. The semi-transparent mirror 12 is mounted on a carriage block 8 which has a key 9 fitting slidably in the guideway 5, 6 and retained therein by a keeper plate 10. A rod 16 fixed at one end to the post 2 has its free end passing through a hole 18 in a swivel pin 14 which is rotatably carried by the carriage block 8. Thus as the camera executes a panning movement, pin 2 rotates and hence the carriage block 8 will slide along the guideway 5, 6, the mirror remaining paralled to the screen. Segments 3, 4 are locked to the bar 1 by respective levers 19, 20 having hooked ends which latch into rectangular holes 25, 26 in bar 1. The other ends 29, 30 of the levers carry rollers 27, 28 which run on the undersurface of a plate 31 which is fixed to the post 2 for rotation therewith. A bracket 35 attached to plate 31 carries a spring-loaded finger 36 on a pivot 37. Thus as the camera pans and rotates post 2, in addition to the movement of the block 8 and mirror 12, plate 31 and its associated parts rotate with the post. When finger 36 reaches one of the rollers (e.g. roller 28 if the plate 31 moves clockwise in Fig.1 the roller is forced into an aperture 34 in plate 1 and retained there. The hooked end of lever 20 comes out of hole 26 and thus segment member 4 is unlocked from bar 1. Further movement of post 2 now moves the whole assembly, including mirror 8 and the member 4, in an arc about post 2. When the apparatus is panned back again (anti-clockwise), member 4 rotates until it abuts bar 1 again, when roller 28 is forced out of aperture 34 and so lever 20 latches once again in hole 26. Block 8 can now slide freely again in guide slots 5, 6 as before. A similar series of actions occurs when post 2 pivots anti-clockwise. The length of the guideway 5, 6 is such that while the screen is in the field of view of the camera the carriage moves along the guideway so that the angular relation of mirror 12, while changing relative to the camera, remains constant relative to the screen. As the carriage arrives at either end of the guideway the screen passes out of the field of view of the camera. At this point the plate 3 or 4 is unlocked from bar 1, so that the path of the mirror now changes from linear to arcuate, so that the angular relation of the mirror to the camera now remains constant.