Movie Types and Film Projection Part 3: Digital Formats

Guest Post: JK

This is part 3 of a 4 part series

With few exceptions, every movie theater now uses digital projection technologies. There are only a select few places theatres that still use film based projection of either 35mm, or the more rare 7Omm and IMAX 7Omm formats. The cost for distributing movies is greatly reduced with digital. Film prints can cost several thousand dollars, 7OMM upwards of $20,000, and IMAX $55,000. Mailing a hard drive with a digital movie costs $300. Having digital projectors also lets the theater run movies without having a dedicated projectionist or projection staff, which further reduces cost to operate a theater or multiplex. There are currently 5 primary digital formats, 2K, 4K, 4K Laser, IMAX Digital, and IMAX Laser.

 

Terminology:
K - The resolution that the digital projector is capable of, or the resolution of the digital movie being projected. K is used as shorthand for ~1000 pixels of horizontal resolution.

Laser - Modern movie projectors primarily use a xenon-filled bulb to project light through film or a digital chip to produce a picture. In the past two years, a new Laser based light source is becoming a competitor, offering higher contrast and more color range.

Resolution - The number of pixels or picture elements used to compose a frame of a movie, represented by two numbers representing the horizontal and vertical counts of pixels. Similar to grains in a film format, but is not directly comparable.

 

2K Digital
The most common digital projectors use 2K Digital, a maximum 2048 × 1556 resolution, or 2 megapixels. The horizontal resolution is 2048 instead of 2000 due to using a base-2 binary reference (2, 4, 8, 16…512, 1024, 2048) instead of a base-10 decimal reference (1, 10, 100, 1000). 2K digital is actually only slightly more resolution than a home theater 1080P system which is 1920x1080 Resolution. In most common use cases, 2K is right around 1080P quality.  Home theater traditionally uses the Vertical resolution as the promotional name (1920x1080) as opposed to the horizontal resolution 2K or (2048x1556). There is added benefit of a larger color spectrum and larger file sizes over home theatre systems, providing higher quality despite the pixel resolution being indistinguishable.

 

4K Digital
Newly built or updated theatres are now using 4K Digital, a maximum of 4096 × 2160 resolution, or 8 megapixels.  4K is 4 times the picture quality of 2K, due to the doubling of height and width pixel counts. (To add to the confusion, Home TV 4K is 3840x2160, different from the cinema standard)

 

4K Digital Laser
The same pixel count and resolution as digital 4K. Laser projection, compared to bulb based projedction, is able to reproduce more colors and solves the issue of light leaks in completely black areas of a movie frame. A laser projector will cast no light in the black areas of a picture. In any other projection technology there is always some light on all parts of the screen, at times giving an odd look to dark scenes.

 

IMAX Digital
IMAX Digital really isn’t much of an improvement over a standard 2K Digital system, due to the IMAX Digital projectors only having a 2K Resolution. The main difference for IMAX Digital is the screen size, which is usually floor to ceiling, wall to wall.

 

IMAX Laser 4K
IMAX Laser 4K again, isn’t much of an improvement over a standard 4K Digital Laser system, due to the IMAX Digital projectors having the same 4K Resolution and image properties.

 

Watch out for “LIEMAX” screens! - Some IMAX screens are put in a traditional theater, but with a slightly larger screen installed. They are not the full size IMAX screens of dedicated installations that often reach dimensions of 80’ wide and 60’ tall. There is an easy way to tell if you are cheated out of the full IMAX experience: If you walk into the IMAX theater, and the screen is not towering over you at least 4 stories tall, (twice as tall as the average theater), you are in a so-called “LIEMAX” that was a converted auditorium or purpose built 2K Digital IMAX. The sound system is still going to be better than a traditional theater, but the picture is probably not much better than what you would experience in any other digital theater, and is usually not worth the ticket price bonus.