2.6.1 65mm (standard 65mm theatrical frame) (Motion Picture Formats - original cinematography)
Description
This article is from the rec.arts.movies.tech FAQ, by Scott E. Norwood snorwood@nyx.nyx.net with numerous contributions by others.
2.6.1 65mm (standard 65mm theatrical frame) (Motion Picture Formats - original cinematography)
The 65mm theatrical film frame is five perforations high (rather than
four for 35mm), and is capable of accepting a wider frame than 35mm
when photographed `flat.' While there have been attempts at fitting
anamorphic lenses onto 65mm cameras (such as `Ultra Panavision (tm)
70'/`MGM Camera 65 (tm) ,' most notably for the film Ben Hur, which
was originally presented in a 2.75:1 aspect ratio), none are presently
in use. While 65mm was once a popular shooting format, it is no longer
in wide usage, with the 1996 production of Kenneth Branagh's Hamlet
being the last major feature to use this film gauge.
It is hoped that the new digital sound formats will eliminate the
magnetic striping used in the past for soundtracks, which contributed
greatly to the cost of this format. Also, the potential exhibition
market for this format is larger than it has been in the past, since
many of the recently-built multiplex theaters have at least one screen
which is capable of showing 70mm, which was often originally installed
in order to show blowup prints of 35mm with the six-track stereo sound
which only the 70m print could provide (prior to the advent of
digital). The DTS digital format was successfully used for the 1996
70mm restoration prints of Vertigo (photographed in VistaVision). In
1997, several 70mm blowup prints of Titanic were struck from the super
35mm negative, also employing the DTS system.
65mm (IMAX (tm) /OMNIMAX (tm) )
The 65mm format is gaining popularity in the growing `ride film'
industry and for `special venue' production in various formats like
IMAX (tm) and IMAX DOME (tm) (formerly known as OMNIMAX (tm) ), which
use film frames of fifteen perforations wide. The film is run through
the camera and projector sideways, just like VistaVision, at fifteen
perforations of length per frame. IMAX (tm) has a projected aspect
ratio of about 1.43:1, but uses a very large screen to achieve its
effect. IMAX DOME (tm) /OMNIMAX (tm) films are shot with the same
cameras and lenses, but are projected onto a domed screen through a
fisheye lens. The screen itself is tilted somewhat toward the
audience, who sit in reclining chairs, arranged in a steeply-sloping
arrangement. Films photographed specifically for the domed screens use
wider lenses which help to reduce the distortion around the edges of
the screens.
There is a similar process to IMAX (tm) , known as IMAX-HD (tm) ,
which uses the same setup, running at 48 frames per second, in order
to achieve a more life-like, better-looking picture.
It is worth noting that none of the formats yet designed by the
Canadian IMAX (tm) company carries a soundtrack on the print. In older
setups, the sound is reproduced from a 35mm 6-track magnetic film
which is run on a dubber-type device, interlocked to the speed of the
projector (and if the power fluctuates significantly during a show,
sync is lost). Newer installations also have the capability of running
the sound off of a CD-ROM disk (as with DTS (tm) ), driven by a
tachometer output from the projector or a timecode on the film; even
when the sound is reproduced from CD, magnetic film is often still run
as a backup. A few films (such as Grand Canyon) used soundtracks
reproduced from 1/2" audio tape, using an 8-track recorder synched to
the projector.
65mm (SHOWSCAN (tm) )
SHOWSCAN (tm) is somewhat of a competitive format to IMAX (tm) and
IMAX-HD (tm) , conceived and supported primarily by Douglas Trumbull
and his Showscan Corporation. It uses 65mm film running vertically at
a rate of 60 frames per second (fps), five perforations per frame,
whereas standard IMAX (tm) , like almost every other format, runs at
24 fps. Supposedly this could give a clearer picture with fewer
`strobing'-type artifacts of the usual double-bladed shutter used for
35mm and standard 65mm (Showscan (tm) and IMAX-HD (tm) both use
projector shutters which show each image only once) and other
shortcomings of the 24 fps standard, in which the projector normally
shows each frame twice (using a double-bladed shutter, which makes one
revolution for each frame), which reduces apparent flicker somewhat.
Formats using the higher frame rate do not appear to flicker anyway,
and thus do not need this `fix.'
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