Film-Tech Forum ARCHIVE: Wow! An article in SMPTE about FILM!

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Posted by John Walsh (Member # 168) on 11-03-2001, 03:17 PM:

There's an article in SMPTE about getting more light on screen by a special-design quick pull down intermittent ("Quickermittent"). The "Quickermittent" can increase light about 36%. This seems pretty good, and worth it if the cost is only a little higher. I'd be worried about maintaince, though.

Does anyone know (to compare): Did those drive-in quick pull down intermittents last as long as a regular intermittent?

There's also a special lamphouse to increase light with a "waffle" or "fly's eye" lens design, with a Cermax integrated lamp package (the lamp has a smaller arc gap, but brighter arc.) The prototype was said to put 16fL on screen with 1500 watts (30 ft wide 'scope screen; 114ft throw.)

While this is certainly more efficient than what you would get using the old rule of thumb (height of the screen, squared X 12, which for this example states you need a 2000w lamp) it does not seem enough of an improvement to pay extra for; ie the same money spent for the next size lamp would provide the required light. Plus, you'd be locked in to one particular type of lamp (though not necessarily manufacturer), which is not a standard type used in most of the industry.

Posted by Gordon McLeod (Member # 33) on 11-03-2001, 05:29 PM:

In the Spring Reps from Kodak demonstrated both at Entertainment Equipments Seminar CTC held in Buffalo
THe quickermittent uses a widened slot in the star to accelerate part of the pulldown

Posted by Dave Macaulay (Member # 813) on 11-03-2001, 07:02 PM:

The Simplex high speed XL intermittents are comparably reliable to the "normal" type if the projector is maintained properly.
They are somewhat more sensitive to oil problems - the sliding bar doesn't like running dry. They are also much more expensive to rebuild if there is a problem.
Don't be alarmed if you come across one somewhere, they have a loud and somewhat alarming sound when running - it sounds a lot like a standard intermittent that's about to fail.

Posted by John Pytlak (Member # 331) on 11-05-2001, 02:28 PM:

The Kodak technical paper "Design Improvements for Motion Picture Film Projectors" is in the November 2001 SMPTE Journal, Volume 110, Number 11, pp.785-791.

Here are links to the Kodak patents, developed to "Enhance the Theatrical Experience":
Kodak Lamp Patent
Kodak Intermittent Patent

Increased efficiency is only one of the many advantages of the Kodak lamphouse design. Illumination uniformity is greatly improved, and the modularity simplifies field alignment.

The faster pulldown of the Kodak intermittent design greatly improves light efficiency, which can put more light on the screen, or allow the use of a three-blade shutter to reduce flicker.
------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Cell: 716-781-4036 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

Posted by Mark Gulbrandsen (Member # 72) on 11-05-2001, 05:33 PM:

David said..."They are also much more expensive to rebuild if there is a problem."

The high speed X-L movements are great, especially with the advent of estar stock. Using synthetics with addatives will make them last far longer and give you some chance of surviving a short dry run. Rebuilding these is no longer possible as parts were discontinued many years ago. If ya know someone with NOS parts you're fine. Otherwise ya better keep a spare movement around.

The higher speed pull down of the Quickermittent will most likely also spell Quickerwearout.....
Mark @ GTS