A film shot in 65mm format is ideally printed and projected using the 70mm film format.
While many modern motion picture productions use 35mm film and high definition (HD) film formats, there are productions that also use the 70mm film format for more specific purposes.
Using 70mm Film
With its larger size, using the wide, high-resolution film gauge 70mm offers a much higher resolution compared to the standard 35mm motion picture format. It is a technically larger container for the captured image; thus, resulting to a better projection quality in very large movie screens.
An interesting thing about projecting movies in 70mm film is that, during the shoot, the film negative used is actually a 65mm film. The movie gets printed onto a 70mm film print (the type of film used for theatrical projection) once the motion picture project hits the theaters. To sum up, the camera used to shoot the movie uses a 65mm film negative; while the film print used during theatrical projection inside the movie theater uses a 70mm film print. The 5mm difference is meant to hold the tracks of the film’s sound. Unlike when using the film negative during the shoot, where the sound is recorded separately from the film stock, the film print used for projection both hosts the visual and sound elements of the movie.
A period in motion picture history (especially by around late 1950s to mid 1990s) showed how a number of movies shot in 35mm films were actually converted onto 70mm film prints for premiere showings in large cities with high-occupancy venues. Drive-in theaters also prefer the use of a 70mm print because of its larger frame area that allows the use of higher intensity light to project a brighter image on large outdoor screens.
70mm vs. 35mm
The 70mm prints are vastly superior to other film formats in terms of providing clearer, sharper, and steadier images on screen. Moreover, instead of the standard four-channel stereo tracks available in the standard 35mm prints, 70mm prints offer six tracks. However, since the introduction of the digital sound formats DTS (Digital Theater Sound, formerly Digital Theater Systems), SDDS (Sony Dynamic Digital Sound), and Dolby Digital, the 70mm print has lost its major sound advantage to 35mm prints.
While more recent 70mm prints can already utilize digital sound recording, the other issue with regards to its use is the fact that standard movie theaters primarily use 35mm film projectors. The cost of investment needed by movie theater operators is too risky for their businesses. The high cost of a 70mm production provides only a limited number of film projects using this over 35mm. With the low demand for 70mm film productions, the more expensive equipment that can cater to such projects isn’t an ideal buy for many movie theaters.
Another advantage of utilizing 35mm over 70mm is that the 35mm film print can readily utilize the regular Cinemascope/Panavision aspect ratio of 2:35 without having to resort to the more expensive 70mm film format. In such cases, 70mm films are then shown in 35mm prints using the Cinemascope/Panavision aspect ratio (offering a widescreen image that has a longer width than the regular 35mm film that only offers an aspect ratio of 16:9). The Cinemascope widescreen format is typically achieved by using the right anamorphic film equipment.
70mm Film Prints in IMAX Theaters and Regular Screens
A number of Hollywood blockbusters originally shot in 35mm are blown up to 70mm IMAX format. While more often used for 3D motion picture offers, even 2D films (usually top blockbuster hits) are blown up to 70mm film and shown in an IMAX theater in 2D format. There are also 70mm projectors that may be used to showcase 3D films on standard-sized screens in multiplexes.