The Super Panatar Variable Type Anamorphic Lens
Operating and installation characteristics of the prismatic optical system developed by Panavision, Inc.
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The 70mm Newsletter
|Written by: ROBERT GOTTSCHALK, President, Panavision, Inc., Hollywood. Calif. MOTION PICTURE HERALD 3 JULY 54. Prepared for in70mm.com by Brian Guckian, Dublin, Ireland||Date: 20.12.2015|
|THE ARRIVAL of the variable anamorphic attachments for projectors has been welcomed by exhibitors. Its arrival means competition among the processes now available. The exhibitor, therefore, has choice. There is no monopoly on special attachments, or wide-screen processes, which marries the exhibitor to any single method of screen presentation. Given that freedom of choice, he has the opportunity to compare processes, and after a careful, studied comparison, he has the opportunity to buy that attachment which suits him in performance, price and availability.|
It is important to distinguish between the two basic types of anamorphic lenses. The first type to appear on the market was the cylindrical lens with an expansion power of two, to complement the camera lenses used in CinemaScope production. Naturally, it is absolutely essential that the projection lens "unsqueeze" the picture in the same degree that the taking lens "squeezed" it in photography. It will be seen therefore that since the optics of a "cylindrical" lens are designed for a fixed power, or magnification, of two, its use is restricted solely to the projection of CinemaScope film.
There is disagreement among the studios as to which anamorphic ratio is the most desirable. This could be a most unhealthy situation for the exhibitor if it were not for the introduction of the variable prismatic anamorphic lens, which is the other basic lens type.
The exhibitor who purchases Super Panatar variable anamorphic lenses can show the present CinemaScope product, and by simply turning a knob on the lens, show any other practicable anamorphic ratio which might come out of Hollywood.
I feel that a word or two about comparison tests should be said at this time. Comparison tests conducted in an unscientific manner can be extremely misleading. Experience has shown that in order to conduct a fair comparison test it is imperative that the following conditions exist: (1) Same objective lens be used with all anamorphic lenses being tested, (2) arc powered by generator, not rectifier, and amperage and trim carefully checked, (3) screen brightness meter held in rigid mount and not moved between tests, (4) same reel of film on each test, (5) proper mounting of anamorphic lens, and (6) proper squeeze ratio set on variable anamorphic lenses.
The writer has been present at many comparison tests and has found few to be conducted scientifically. I recall one in particular where two different makes of cylindrical lenses were compared. One was rated as having a much greater light transmission than the other. Knowing this to be an optical impossibility, I objected to the findings, even though the Super Panatar was not involved. A second test with more rigid control indicated equal transmission.
As far as the quality of projected image is concerned I strongly recommend the exhibitor to pay particular notice to the sides of the picture. It is here that the exhibitor will notice a definite difference both in respect to sharpness and amount of distortion of image.
The Super Panatar uses what is called thermo-setting plastic for cementing lens elements, as opposed to the less durable and less expensive balsam cement. And installation of the Super Panatar lens is very simple.
The fact that various anamorphic processes are in the field is itself one of the healthiest things that has happened to exhibition. Exhibitors would be wise to avail themselves of every opportunity to make comparisons of attachments available.
The Super Panatar prismatic projection lens for expansion of squeeze prints is pictured above as mounted on a projector, seen from the port side. The Super Panatar is not attached to the lens mount, but to the mechanism frame. For this, on acceptance bracket is supplied, consisting in a pad which is first bolted to the projector, and the lens bracket itself. This type of mounting has been designed to control lateral tilt of the lens so that the lens is in a level position regardless of the angle of the projector, thus to make horizontal lines of the picture, when projected on a curved screen, appear straight from the main floor.
By means of pivot pins, the lens is mounted on the bracket and aligned exactly with the projector optical system, finally checking this alignment (before locking the lens firmly in position) by projecting a picture or target film on the screen.
The knob pictured on top of the lens, near the front, is an "aspect ratio control" knob. By means of it, the proportions of a squeeze picture projected at full aperture can be changed from the aspect ratio for which the print was made. This procedure, producing expansion at a different rate from that of compression, is said to be allowable if it causes distortion no greater than 5%. In projecting cartoons, and title material, some believe that distortion may be practically ignored altogether.
Prism surfaces of the Super Panatar may be cleaned by removing screws which hold the lens housing to the chassis and removing the chassis from the housing. The prism can then be cleaned without being detached from the chassis, which the manufacturer warns, must never be done.
|More in 70mm reading:|
Panavison Large Format Motion Picture Systems
The Importance of Panavision
Super Panavision 70
Ultra Panavision 70
Ultra Panavision 70 Lens
"The Motion Picture Projectionist"
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