GB2112535A - Panoramic camera - Google Patents

Abstract

A scanning panoramic camera of the rotating optical bar type comprising two lens systems (13, 15) separated by a double sided mirror (9) rotating on the same optical axis using two rolls of film, (4, 4A) one per lens system, with each roll of film accepting alternate exposures to facilitate stereographic viewing after development. The rolls of film may be used successively for covering a greater distance of non stereographic photography. <IMAGE>

Description

SPECIFICATION Improvements in or relating to panoramic photo- graphy This invention relates to panoramic photography and more particularly, though not exclusively, to stereographic panoramic photography as more generally applied to cameras sited in airbourne containers.

Panoramic cameras of the rotating optical bar type are well known, G.B. Patent 1519569 discloses the operation and G.B. Application number 8016301, to be accorded Ser. No. 2076980 discloses a method of roll stabilising the image motion compensation.

With this type of camera used in the across track mode, i.e. from one side horizon, through the vertical, to the other side horizon, two cameras have been used for stereographic photography. As the rotation of the optical bar in each camera is continuous the two cameras are started out of phase, so that, even though the movement of the webs or photographic medium is continuous and rotating on the optical bars, the cameras are actually exposing the webs alternately as each exposing slit passes across its web. This causes two main problems, one is the synchronisation of the cameras and the other is the additional weight, i.e. two cameras. This type of camera used as a single unit is often required to take panoramic photographs over a longer distance than originally designed for, so larger magazines have been fitted to accommodate the additional web required.Again this has caused problems in so much as the space provided, expecially in pods underslung on an aircraft wherein the diameter of the pod is the ruling factor, is invariably two small to accommodate the enlarged magazine. Furthermore the physical handling and processing of the excessive continuous length of film is difficult. Another method of stereo viewing of panoramic films has been to cut the exposed film into individual frames and then join the frames down their long sides.

Again it will be obvious that this is a long and tedious process which will be overcome with the present application.

It is therefore an object of this invention to provide a panoramic camera which may be used for stereographic photography wherein the problem of synchronisation is substantially eliminated, at the same time provide a panoramic camera which will fit into a pod or the like of the same diameter as previously but will at the same time be capable of providing the additional photography required and make film management more acceptable.

According to the invention we provide a scanning panoramic camera having, a rotary optical bar which comprises a first light path deflection means, a first objective lens, a second light path deflection means operable to deflect the light path of the said first objective lens, a first exposure slit which rotates about the optical axis of said first objective lens and transmits a portion of the light path deflected by said second light path deflection means, a third light path deflection means back to back with said first light path deflection means, a second objective lens on the optical axis of said first objective lens, a fourth light deflection means operable to deflect the light path of said second objective lens, a second exposure slit which rotates about the optical axis of said first lens and transmits a portion of the light path deflected by said fourth light path deflection means, said scanning panoramic camera further comprising a first feed and take-up means for a first web operating in conjunction with said first slit of said rotary optical bar and a second feed and take-up for a second web operating in conjunction with said second slit of said rotary optical bar.

The invention will now be described by way of example only, in conjunction with the accompanying drawings in which, Figure 1 shows the basic end view of a scanning panoramic camera Figure 2 shows a side view of the rotary optical bar and, Figure 3 shows the principle of operation.

Referring now to Figure 1 a scanning panoramic camera has a body (1) of which only one end view is shown as the opposite end is similar. Mounted on the body (1) are two feed cassettes (2), only one shown and two take-up cassettes (3), only one shown. Two webs (4) and (4A), only one shown, are driven by two drive rollers (5), only one shown, from the feed cassettes (2) to their respective take-up cassettes (3) via miscellaneous rollers (6) and their respective ends of a rotary optical bar (7) in which two slits (8) and (8A), which may be adjustable in width, are formed.

Referrring now to Figure 2 the rotary optical bar (7) rotatable in the body (1), has a first light path deflecting means (9) which may be one side of a double sided mirror, one of two prisms with their largest single surfaces joined together or one reflective surface of any other known means of deflecting two facing light paths through approximately 90 degrees to form two receding light paths. The light path deflecting means (9) may be pivoted at (10) so that the deflecting angle may be varied. A sliding pin (11) operating between the light path deflecting means (9) and a swashplate (12) may be incorporated to provide image motion compensation for counteraction of the forward movement of the camera in flight.A first objective lens (13) operable to focus an image from the first light path deflecting means (9) transmits the image via a second light path deflecting means (14) on to the first web (4) via slit (8). Athird light path deflecting means, which, in this example, is the reverse side of the first light path deflecting means (9) impinges its image into a second objective lens (15) which focuses the image via a fourth light path deflecting means (16) which may, as may the second light path deflecting means (14), be a mirror, prism or any other known means of deflecting a light path through approximately 90 degrees. The light path deflected by the fourth light path deflecting means (16) passes via slit 8A on the second web (4A) when in alignment.

Referring now to Figure 3 wherein the principle of operation is shown at three stages (a), (b) and (c) it will be noted that the web (4) rotating clockwise at stage (a) is about to start recording an image received from horizon (17) passed via the back of deflecting means (9) through the first objective lens (13) deflected again by deflecting means (14) and thence, via slit (4) not shown for clarity, rotating counterclockwise. Web (4A), rotating clockwise, has justfinished recording the deflected image from horizon (18) which was received via the front of deflecting means (9), objective lens (15), deflecting means (16) and slit (8A), not shown for clarity, rotating counterclockwise.On web )4) it will be noted that frame (19) is exposed and fully wound on, frame (20) is about to have its exposure started and frame (21) is also fully exposed with half the frame wound on past roller (6D) and the remainder of the frame is wrapped around the optical bar (7) as far as roller (6C).

At (b) the back of deflecting means (9) is pointing vertically downwards and is receiving an image from directly beneath the flight path and as shown by the dotted line across the web (4) it is exposed for half a circumference of the optical bar (7) with a quarter of the circumference already fed past roller (SB). Web (4A) is still being wound on with three quarters of the frame past roller (6D) and a quarter left to be transported. Deflecting means (16) is deflecting its image away from the web (4A).

At (c) the back of deflecting means (9) is pointing to horizon 18, the exposure of frame (20) on web (4) is completed and half of frame (20) has been wound on. The front of deflecting means (9) is pointing to horizon (17), frame (21) of web (4A) has been fully wound on and exposure of frame (22) of web (4A) is about to commence. The remainder of frame (20) on web (4) will, on the next half cycle of the rotating bar, be fully wound on.

it will be obvious to one skilled in the art that a frame on web (4A) commences half way through a frame on web (4) so that after processing the two webs may be laid parallel on a light table and stereo viewing through a stereo viewfinder made much simpler as there is no problem of matching up frames from two cameras or cutting and matching the frames from a single camera.

In the case of providing additional photographic coverage, web (4A) drive may be stopped and made to operate when web (4) has been fully exposed and the last frame is being wound on. By using the two feed magazines successively twice the distance may be covered with no increase in the diameter of the pod or container.

Claims (10)

1. A scanning panoramic camera having, a rotary optical bar which comprises a first light path deflection means, a first objective lens, a second light path deflection means operable to deflect the light path of said first objective lens, a first exposure slit which rotates about the optical axis of said first objective lens and transmits a portion of the light path deflected by said second light path deflection means, a third light path deflection means back to back with said first light path deflection means, a second objective lens on the optical axis of said first objective lens, a fourth light path deflection means operable to deflect the light path of said second objective lens, a second exposure slit which rotates about the optical axis of said first lens and transmits a portion of the light path deflected by said fourth light path deflection means, said scanning panoramic camera further comprising a first feed and take-up means for a first web operating in conjunction with said first slit of said rotary optical bar and a second feed and take-up means for a second web operating in conjunction with said second slit of said rotary optical bar.

2. A scanning panoramic camera as claimed in Claim 1 wherein each, or any, of the light path deflection means comprises mirrors.

3. A scanning panoramic camera as claimed in Claim 1 wherein each, or any, of the light path deflection means comprises prisms.

4. A scanning panoramic camera as claimed in Claim 1 wherein said first and third light path deflection means is pivoted and controlled to provide image motion compensation.

5. A scanning panoramic camera as claimed in Claim 4 wherein said control for image motion compensation comprises an actuator in contact with the surface of a swashplate and operable on said light path deflection means.

6. A scanning panoramic camera as claimed in Claim 1 wherein each, or either, of said slits in said rotary optical bar is adjustable in width.

7. A scanning panoramic camera as claimed in Claim 1 wherein said webs are independently driven.

8. A scanning panoramic camera as claimed in Claim 1 or Claim 7 wherein said webs are synchronously driven.

9. A scanning panoramic camera as claimed in Claim 1 or Claim 7 wherein said webs are successively driven.

10. Ascanning panoramic camera substantially as described herein in conjunction with the accompanying drawings.