posted 01-18-2005 12:11 PM                       

quote:

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Perforations
Why All the Sizes and Shapes?
In the early days of 35 mm motion pictures, film perforations were round. Because these perforations were more subject to wear, the shape was changed to that now known as the Bell & Howell (BH) or "negative" perforation (Figure 41). This modification improved positioning accuracy and was the standard for many years.

During this time, 35 mm professional motion picture cameras and optical printers were designed with registration pins that conformed to negative (BH) perforation. To this day, newly designed professional equipment incorporates registration pins conforming to the negative (BH) perforation. In 1989 Kodak introduced a stronger version of the Bell & Howell (negative) perforation. The radius of each corner was rounded by 0.005 inches. This small difference is almost imperceptible visually, but adds strength where the perforation is most vulnerable to tearing during stress periods while being transported through equipment. This is especially true during highspeed photography. This corner radius change does not necessitate any equipment change worldwide, and yet improves product performance.

Another Bell & Howell perforation performance improvement was introduced by Kodak in 1989. This is a reduction in perforation-dimension tolerance from the ANSI specifications. This tighter tolerance format is used where film registration is very critical, such as in travelling matte photography or separations. The tighter tolerance perforations are standard on all Kodak 16 mm camera films and some 35 mm films.

The high shrinkage of older films on nitrate base made the negative perforation a problem on projection films due to excessive wear and noise during projection as the sprocket teeth ticked the hold-back side of the perforations as they left the sprocket. The sharp corners also were weak points and projection life of the film was shortened. To correct this, a new perforation was designed with increased height and rounded corners to provide added strength. This perforation, commonly known as the KS or "positive" perforation, has since become the world standard for 35 mm projection print films.

During the period when the production of color prints involved the multiple printing of separation negatives onto a common print film, a third design, known as the Dubray-Howell perforation, was introduced. It had the same height as the negative (BH) perforation to maintain the necessary registration but had rounded corners to improve projection life. This perforation is still available for special applications on certain films. Because shrinkage in current films is low, the shorter perforation height poses no projection wear problems. In 1953, the introduction of Cinemascope produced a fourth type of perforation. This wide-screen projection system incorporated 35 mm film with perforations that were nearly square and smaller than the positive (KS) perforation. The design provided space on the film to carry four magnetic sound stripes for stereophonic and surround sound.

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Perhaps the print you had was originally made for a pin-registered application, and they kept the print for theatrical use. Or someone grabbed the wrong cans of raw stock.

posted 01-18-2005 12:31 PM                    

quote: Leo Enticknap

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maybe the BH stock was more readily available in 2k lengths rather than the 6k rolls which I understand are more commonly used on the high-speed printers that produce large-scale runs of prints? Just a speculation.

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Might be the case. There were NO lab splices in any of the 12 reels

posted 01-19-2005 12:30 AM                      

quote: Dan Lyons

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It had heavy grain and poor contrast. In some scenes I felt like I was watching an Eastman print, in some shots the blacks were not black, but had a brownish/red look. The color timing between shots within some scenes varied, and color timing between reels was also off.

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posted 01-20-2005 06:02 AM                       

quote: Tao Yue

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Plus he has a reputation for shooting very thick negatives so that'd aid in dye preservation.

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posted 01-20-2005 12:49 PM                       

quote: Leo Enticknap

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In fact that would probably exacerbate the fading, thereby requiring heavier correction when printing seps for preservation.

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posted 01-20-2005 04:17 PM                       

quote: John Pytlak

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Since dye fading is usually manifested as a loss of contrast or buildup of stain, a denser, "richer" negative is usually better. There's more image to begin with, and less unreacted coupler chemistry left in the film.

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posted 01-21-2005 08:01 AM                       

quote: Leo Enticknap

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Surely the denser emulsion will absorb more light in printing and therefore need greater refraction to correct the colour balance on the dupe?

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