Bell & Howell perforations on still film

Mr Bill said:

Thanks Kino! After a brief look into the book I'm finding a lot of details that I never realized I was interested in!

I would imagine that relatively few of the various printer types were ever made, and am a bit saddened that once they are gone this sort of thing will likely never be made again.

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Yes, they were not made by the hundreds of thousands, maybe a thousand per if very popular, but most have long been scrapped.

The precision machining required to reproduce some of these printers would put them in the millions of dollars a copy.

the massive size of the machines is shown by this ad for the capabilites of one US film Lab. http://colorlab.com/film/film_printing.html Note that they say they print 16mm film at 240 feet a minute. 240 feet of 16mm is a running time of 6 minutes and 40 seconds when shown in a projector. so they could make a 16mm print that runs an hour in about Nine minutes on their printer. (plus processing time of course.)

and historian Brian Prichard does have a page on the Bell and howel Model C.

Thanks for the links, Charles.

cmacd123 said:

...that even had the "Eastman Safety film" edge print, along with still frame numbers.

Good catch.

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To follow-up, the images came-out fine...not bad for a film that expired 66 years ago (as of 2024). It says "Kodak Safety Film" and has still frame numbers, albeit "upside down."

Triangle square Date code could indicate 1924, 1944 or 1964. Although the first two are Highly unlikely. and do not correspond with the listed expiry date. S'AFETY would indicate Rochester NY Factory.

The development of the BH Perforation and its full acceptance for use date back to the 1910 time-frame. Initially, a circular perforation was developed (I think by users in Europe), and the BH perforation or its early variant, (I think developed and used by Edison's team), simply modifed the circular hole. In that time-frame, Kodak was not perforating film...simply selling slit rolls where customers could perforate the film in the format their equipment would use. The BH perforation was finalized by Bell & Howell, the original manufacturer of reciprocating perforators, by taking the circular perforation and reducing it by adding two flats to it.

Once the Society of Motion Picture Engineers was formed and developed a formal standard for perforation placement, design, and dimensions, Kodak began purchasing equipment to perforate film. That happened in the 1916 time-frame. All equipment back them utilized the BH perforation. The equipment in cameras to advance the film and fix the position utilized the shape of the BH perforation to lock-in positioning for improvements in steadiness through the entire process.

The KS perforation, developed by Kodak and approved by SMPE (now SMPTE), was implemented for distribution type films because repetetive use of the BH perforation in conveying projected prints was leading to film fracture from the angled points of the BH perforation - the place of greatest stress concentration. The KS hole reduced the damage and allowed theaters to show prints longer without fear of the film breaking due to the tearing at the perforations.

There were questions as to why the BH perforation remained in use for camera negative and lab films. SMPE would have had to approve such a change and that never occurred, although some of the documentation I saw when I worked inside Eastman Business Park did indicate that Kodak did propose that a long, long time ago.

When 35mm consumer and professional film began, the KS hole was used for this format because the cost to manufacture the punches and dies was much less than that for the BH hole. The same is true for the 65mm / 70mm films which came in after the KS hole and all films are made with the KS hole.

CMACD123 mentioned a "Duvray Howell" perforation. The name is Dubray-Howell, and was a perforation which was implemented for full-fitting precision step optical printers, where film "stacks" were being printed onto an intermediate. (Think of "Star Wars" spaceship battle scenes where upwards of 16 pieces of original camera negative were "stacked" onto intermediates to create the scene with lazer blasts, explosions, and many spacecraft models. All that is now created in digital space so the need for the DH film ended, though as of a few months ago, tooling was still available in the factory.

Now, the original roll shown with BH perfs and a totally blank "Kodak Yellow" cassette sounds like this roll was some sort of test film cassette. I remember in the mid-1980's, we utilized blank metals for test cassettes when new films were sent for testing. I may still have one of the Kodachrome 200 in my collection. We did manufacture some products with a BH perforation back in the late 1980's, but I no longer have access to those formal prduct lists and information, as I have now left that wonderful factory.

cmacd123 said:

Triangle square Date code could indicate 1924, 1944 or 1964. Although the first two are Highly unlikely. and do not correspond with the listed expiry date. S'AFETY would indicate Rochester NY Factory.

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Thanks! Would the word "safety" have been printed differently, at different Kodak factories?

FredK said:

The development of the BH Perforation....

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Thank you for such a detailed analysis! I did not realize there was "that much" that went into development of the different perforation types, including bureaucracy. But when "you" realize what is actually involved, in getting a film (movie) production from the set to the screen, it all makes sense.

MultiFormat Shooter said:

Thanks! Would the word "safety" have been printed differently, at different Kodak factories?

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Kodak used a small dot between the letters of the word Safety to indicate the production location.

the film is the picture has a small dot just near the A

S'AFETY =Rochester
SA'FETY = Toronto
SAF'ETY = London. and so on.
one thing to watch is that Windsor Colorado did some Movie stock and it was labeled like SAF,ETY just ot be confusing.

after the safety wording finally became of only historical interest, the marks were instead placed on the word "KODAK" if you look closely, I belive that is the case even now, of course only Rochester is curently a production site K'ODAK It also may not be the case for film with KEYCODE edge print.

FredK said:

There were questions as to why the BH perforation remained in use for camera negative and lab films. SMPE would have had to approve such a change and that never occurred, although some of the documentation I saw when I worked inside Eastman Business Park did indicate that Kodak did propose that a long, long time ago.

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I had heard the story that the switch to KS perfs was proposed at some interational Meeting (posiblely the ISO) and the Soviet Union was enthusiastic, but other folks were not wanting to change.. (probably cameras and printers would have needed new sprockets) so the Soviets used KS for everything, while the europen and North American industry stuck with BH.

I also read "somewhere" that Kodak has in the last decade changed the radius of the corners of their KS perfs. again to reduce the stress on the corners. This might have been when they went to the rotary Perforators that @laser metioned a while back.

I seem to recall the change to KS for everything was proposed at an ISO standards meeting just prior to WWII in Budapest, Hungary, but only the Soviet Union adopted that strategy.

I worked with Unites States origin elements that ranged from 1894 (Edison's first experiments) to the late 1970's. Perforation shapes from 1984 to 1909 (roughly) were all over the map, but in-large roughly the shape that would become the standard BH perforation.

It was in 1909 that Bell and Howell started selling the trifecta of the 2709 Camera, the Reciprocating Perforater and their contact printer and this (at least in the USA) set the standard for perforations for years to come.

"Technological History of Motion Pictures and Television : An Anthology from the Pages of "The Journal of the Society of Motion Pictures and Television Engineers" edited by Raymond Fielding is a good book to peruse for many obscure facts about early motion picture production; including film stock production.

cmacd123 said:

I had heard the story that the switch to KS perfs was proposed at some interational Meeting (posiblely the ISO) and the Soviet Union was enthusiastic, but other folks were not wanting to change.. (probably cameras and printers would have needed new sprockets) so the Soviets used KS for everything, while the europen and North American industry stuck with BH.

I also read "somewhere" that Kodak has in the last decade changed the radius of the corners of their KS perfs. again to reduce the stress on the corners. This might have been when they went to the rotary Perforators that @laser metioned a while back.

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The radius change you reference for the KS perforation occurred around 1991. It was done to reduce stress concentration as with print stock not converted to polyester and the mega-plex theaters being small seating, prints were being shown more than prior decades and some prints experienced failure from the corners.