3-Perforation

Instead of a traditional 4 perforation movement, which advances the film 4 perforations for each new image, a 3 perforation movement advances the film only 3 perforations, thus eliminating the previously unused space between frames. This results in a 25% savings in film stock and lab costs with no reduction in image quality. In addition, the film in each magazine lasts 33% longer, making film production more efficient.

How 3 Perforation works
For a basic introduction to 3 perforation watch this clip.

Most wide screen 35mm projection formats, including 1.85 and Super 35/2.35, do not use the full 4 perforation height of the 35mm frame. They fit easily between 3 perforations. In fact, the only two formats that use the entire 4 perforation height for picture information are anamorphic photography and material originated specifically for 4:3 full-frame TV transfer.

ARRI supplies optional 3 perforation movements, format masks and groundglasses for the ARRIFLEX 435 and 535, and for the ARRICAM System.

3 perforation has been used extensively for television series to reduce production costs while still retaining a high quality 35 mm film master, which can be transferred to any future video format if needed. All modern telecines can accommodate film shot at 3 perforations per frame. But in the past theatrical productions have shied away from 3 perforations because of the difficulty of creating a 4 perforation release print from a 3 perforation negative.

With the advent of the Digital Intermediate and the fast rising popularity of the ARRILASER, two closely related developments, many producers are now looking at shooting 3 perforation for a theatrical release.

The Digital Intermediate process makes it possible to scan the complete 3 perforation negative, perform all post-production steps in the digital realm, and then use the ARRILASER to record the images back onto 4 perforation Internegative (IN) or Interpositive (IP) to create standard spherical or anamorphic 4 perforation release prints.

Changes in lab processes have also improved the quality of the optical step necessary to go from a 3 perforation negative to a 4 perforation release print, providing a second alternative.

It doesn't matter which way you go in post - analog or digital:
3 perforation offers the most efficient and economical way to 35mm film production.

Cinematographers, who like the flexibility and creative options provided by the Digital Intermediate, have successfully argued that the savings of 3 perforation can offset most or all of the cost of the Digital Intermediate. When going the Digital Intermediate route, there is no reason not to shoot 3 perforation.

For more information about 3 perforation and a historical perspective, here are some articles (Thanks to David Mullen, a Cinematographer from LA, for sharing his research):

" In the Sept. 1973 issue of the SMPTE Journal, pg. 742, is an article titled "A Universal Format for Film Production" by Bernstein, Wysotsky, and Konoplev. It is a translated reprint of an article in Tekhnika i Kino Televideniya of January1973. It recommends shooting in 3-perf full-aperture as a way of generating either 1.85, 2.35 anamorphic, or 4:3 TV versions from the same negative.
" In the March 1975 American Cinematographer magazine is an article by Kenn Davis proposing a new lens system with a 25% anamorphic squeeze, in order to get a 1.85:1 image onto a regular 16mm frame, and a 2.35:1 image onto a 3 perf 35mm frame. He then goes on to explain other advantages of a 3 perf system, including for 1.85 production.
" In the June 1976 American Cinematographer magazine is an article by Miklos Lente, proposing a 3 perf format called "Trilent-35". It used the Academy width but the 3-perf height.
" In the July 1986 American Cinematographer magazine is an article by Rune Ericson titled "3-Perf in the Future".
" In the February 1998 issue of "International Photographer", Vittorio Storaro proposed his "Univision" 3 perf Super35 format.

For the technically minded, the dimensions of the two ARRICAM format masks for 3 perforation are:

3P HDTV S35 1.78 (ANSI):	24,9 mm x 13,9 mm (0.98" x 0.547")
3P TV 1.33:	22 mm x 13,9 mm (0.866" x 0.547")

ARRI cameras available with 3 perforation movements:

ARRICAM Studio
ARRICAM Lite
ARRIFLEX 435 Advanced

Please download the ARRI Technologies - 3 Perforation brochure as pdf-document and visit the article on Integrated Capping Shutter for 435 3 Perforation (ARRI Newsletter 09/2003 - IBC Edition)

TECHNICAL SPECIFICATIONS:

Cost:
25% less raw stock, dailies, answer prints, Intermediate Positive. Savings in developing, preparation, cleaning and handling of negative Additional film savings due to fewer short ends with extended magazine running times

Shooting Time per Magazine:
33% more running time, longer takes. Extended running time with 400ft/120m lightweight magazines for handheld work. More takes per magazine.

Capture Requirements:
35mm camera with 3 perforation movement (e.g. ARRICAM Studio and Lite, ARRIFLEX 435, ARRIFLEX 535B)

Sound:
No difference between 3 perforation and 4 perforation production

Post Production Requirements:

Video dailies:	Telecine with 3 perforation capability (e.g. Spirit, Genesis, C-Reality)
Film dailies:	3 perforation film projector for screening dailies (e.g. ARRI Locpro 35)
Editing:	Nonlinear editing system (e.g AVID, FCP) with cut list output in 3 perforation
Theatrical release optical process:	optical printing from 3 perforation negative to 4 perforation Intermediate Positive or Intermediate Negative.
Theatrical release digital intermediate:	Scanning of negative, then recording on 4 perforation Intermediate Positive or Intermediate Negative (e.g. ARRILASER)

Formats available for ARRICAM and ARRIFLEX cameras:

Normal 35 (ARRICAM only):	1:1.33 - 3P safe/trans
Normal 35 (ARRICAM & ARRIFLEX):	1:1.66, 1:1.78, 1:1.85, 1:1.33 - 3P trans
Super 35 DIN (ARRIFLEX only):	1:1.78 safe, 1:1.85, 1:2.35 centric, 1:2.35 off center
Super 35 ANSI (ARRICAM & ARRIFLEX):	1:1.85, 1:2.35 centric, 1:2.35 off center

Technical Data are subject to change without notice.