Using the Cinerama Camera
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The 70mm Newsletter
|Written by: Harry Squires||Date: 09.01.2010|
|Cinematographer Harry Squires behind Cinerama camera.|
The Cinerama camera, because of its extremely wide angle of view, 146░ horizontally and 55░ vertically, presents problems not found in other motion picture cameras. The system uses three lenses, takes a picture of a unified field on three separate pieces of film simultaneously, and integrates them into one picture on the screen in the process of projection.
The two places where the three images overlap, namely the matchline areas might be a distinct source of trouble in the taking of the pictures as regards to the subject placement on the set unless certain things are known about the system. The following material is a discussion of the features that have been observed or points of knowledge that have been gained from experience in using the camera.
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in70mm.com's Cinerama page
Setting Up The Camera
|Remove the camera from the trunk and set it on a tripod, a velocelator or some other suitable means of support. The camera is heavy and therefore needs a sturdy means of support in order to insure camera steadiness. Locate the camera with relation to subject to be photographed with due consideration to the framing, the distance, the camera angle, and the anticipated movement of the subject and the camera. Space should be allowed near the camera for the chamber trunk or chamber rack to facilitate the chamber removal from the camera and to provide a safe place for the chambers when they are removed for the purpose of reloading them or for using the direct viewers.|
|1. Setting Up The Camera|
2. Framing - Parallax
3. Image Size - Perspective
7. Camera Movements
8. Subject Movements
|The framing of the scene can be observed by installing the direct viewers, looking through them one at a time and integrating the total view mentally. The direct viewers go directly behind the camera lenses, therefore, there is no problem or parallax when they are used there. The "B" direct viewer is used in conjunction with the combination viewfinder on top of the camera. Here there is a problem of parallax. This is taken care of with the focusing knob on the right hand side of the viewfinder. This knob not only focuses the viewfinder but also adjusts the parallax for the distances indicated on the side of the focusing knob.|
The viewfinder for the #3 blimp is an optical viewfinder which shows all three sections of the picture simultaneously through one eyepiece. This viewfinder cannot be used with the other blimps or with a camera alone until they are adapted.
|The lenses of the Cinerama camera have a focal length of 27mm and have a far greater angle of view vertically than even an extremely wide angle lens on a regular 35mm camera. The image size, therefore, is comparatively small and in order to get an (a line of text is missing) ECU shot, the camera has to be extremely close to the subject; even as close as 18 inches or less. With lenses of short focal length it is possible to get greater perspective, that is, objects in the foreground appearing large and those in the background appearing small. This is even more apparent with the Cinerama camera because of the three lens system and the extremely wide angle of view.|
|Horizontal lines above and below the optical axis of the lenses have a tendency to curve slightly and also show a definite break in continuity at the match-lines which gives an unreal effect of angularity. Even straight horizontal lines on a level with the lenses' axii which record faithfully on the film will appear curved on the screen to some observers because of the curved screen used with the system. For the least disturbing effects, therefore, it is of an advantage to avoid shooting subjects which possess or form a pattern of straight lines. When the Cinerama camera is tilted up or down, vertical lines converge as would be expected, but with the Cinerama camera the convergence is much more noticeable and each field might appear to converge to a slightly different apex. Because of this characteristic of the Cinerama camera, discretion should be exercised in tilting the camera upwards or downwards, except under closely controlled conditions or for extra ordinary purposes. These effects can be an obstacle or an asset and the cameraman should be aware of them so that he can use them to the best advantage.|
|The three lens optical system of the Cinerama camera is such that it is difficult to have match-areas which are perfect at all distances from the camera. The camera is so designed that the point of best match is at that distance at which the camera is critically focused. If the subject is on the match-line the camera should be focused on that subject if good overlap and match is to be expected or desired. Objects closer to the camera than that have a tendency to become broadened or enlarged while objects farther away overlap and disappear. For example, it is possible for a complete letter in a sign in the background to completely disappear when that letter is on the match-line and the camera is focused at a point close to the camera. On the other hand it is possible for a person's face, if it is on the match line close to the camera, to be broadened to grotesque proportions when the camera is focused on a distant object, even to the extent that the person might appear to have two noses or three eyes.|
Action, too, will be distorted if it takes place on the match line unless the camera is focused for that action. A person or object going from one section of the screen to another might jump ahead, appear in two places at one time, or completely disappear momentarily if it does not cross at the point of (a line of text is missing).
It is important that the cameraman know this in order that he have the principal subjects, if on the match line, only at the point of focus. This phenomenon is a product of the characteristics of the camera and must be dealt with; it cannot be eliminated. The focusing, therefore, in most cases must be a compromise between the main subject and the subjects on or passing through the match-line. The redeeming feature about the Cinerama camera is that because of the short focal length lenses, the depth of field is sufficiently great (even with the lens wide open) that critical focus is not a serious problem.
Focusing the camera is carried out with a knob located between the "B" and "C" magazines. The figures on the knob are in feet.
|The Cinerama camera intermittent has a six perforation pulldown and a standard frequency of 26 frames per second. This gives a speed of film through the camera of 146╝ feet per minute (2-7/16 feet per second). A footage counter located near the focus knob records and accumulates the amount of film that goes through the camera. It is calibrated in feet.|
The shutter on the Cinerama camera (#2 to #5) is a fixed blade shutter with an opening of 165░. At 26 frames per second the shutter speed with regard to exposure is approximately 1/60 of a second (1/57 of a second, to be exact.) Number 1 camera has a shutter opening of 151░ which, at 26 frames per second gives a speed of 1/62 of a second.
The lens apertures are set by turning a small knob located at the top of the camera between the "A" and "B" chambers. The dial is calibrated in f/stops from f/2.8 to f/22. The zero on the dial indicates the closed position of the diaphram. The diaphrams on all three of the lenses are connected to the one control and work simultaneously. This is the only means of setting the exposure on the camera unless the camera is run at some speed other than 26 frames per second.
Since all three diaphrams are operated simultaneously, it follows that the exposure for the different lenses cannot be changed one to the other in spite of the fact that the subject taken by one lens might be front lighted, that by a second side lighted, and that by the third back lighted.
The inadvisability of changing the exposure between lenses can be readily understood when it is realized that doing this would bring about a more serious and difficult problem, that of matching the three films at the match-line both in density and color. From experience it has been found that this condition can be handled by a mean exposure, since the latitude of the film can absorb most of the deficiencies in lighting of this sort.
|Camera movements are necessary in cinematography, but the Cinerama camera movements should not be used too freely and should be limited to the necessity of the movements for cinematic effects. Panning should be used sparingly, and if done, done (a line of text is missing) the result. However, lateral dollying has been used very effectively. In the forward movements of the Cinerama camera, such as in trucking shots, an extreme illusion of movement is obtained and, unless violent action is desired, this should be done slowly, especially when the camera is close to the subject. Excellent zooming effects have been obtained by rapid forward movement of the camera, such as on a roller coaster, on a bobsled, and in the nose of an airplane when it is close to a solid object. When the airplane is at a high altitude, the illusion is that of a slow trucking shot.|
Subject Movements and direction
|The three lenses of the Cinerama camera point in different directions. Therefore, the three fields of the Cinerama camera could be taken by three separate cameras, each pointing in a different direction. Because of this, the perspective in each picture or field, is different. This means that the movement or the direction is different in all three pictures, that is, a person moving, walking or looking in a certain direction in one picture would not appear to be moving or looking in the same direction in the other two pictures. Therefore, in order to have some sort of consistency of direction, some compensation with respect to the movement direction has to be made -- that is, to make it appear that a subject is moving or looking correctly from one field to the other.|
In the Cinerama process, with a person in one field looks directly at a person or a thing in another field, the person appears to (a line of text is missing)
|An attempt has been made to discuss objectively, some of the features, characteristics, and phenomena of the Cinerama camera. In the system there are some drawbacks as well as advantages, which tax the cameraman's ingenuity, but which, if understood, allow him to go far beyond anything he has done in conventional cinematography. It is hoped that most of the points of difference between the conventional camera and the Cinerama camera have been at least mentioned here, if not comparatively discussed. None of this should be construed to mean that any or all of the features or phenomena of the Cinerama camera be used or avoided at all times, but rather that they should be analysed, understood, and used within the pattern of common sense and good taste. The only criteria by which the features, good or bad, of the Cinerama camera can be judged is: Does it give the desired artistic, dramatic, or cinematic effect without obvious or universal distraction?|
It is admitted that this system has problems and drawbacks that might prevent the cameraman from shooting some scenes with ease, but, like other liabilities in motion pictures, these too can be used to heighten the interest, suspense, mood, and tempo of the film, if they are understood and used judiciously. For the cameraman who know, understands, and uses the Cinerama camera, there is an opportunity to discover and exploit a completely new means of cinematic expression.
The fields in which the Cinerama camera can be (a line of text is missing)
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