Anamorphic Widescreen - Film

Film

Many commercial cinematic presentations (especially epics – usually with the CinemaScope 2.35:1 optical sound or the older 4-track mag sound 2.55:1 aspect ratio) are recorded on standard 35 mm ~4:3 aspect ratio film, using an anamorphic lens to horizontally compress all footage into a ~4:3 frame. Another anamorphic lens on the movie theatre projector ultimately corrects (optically decompresses) the picture. See anamorphic format for details. Other movies (often with aspect ratios of 1.85:1 in the USA or 1.66:1 in Europe) are made using the simpler matte technique, which involves both filming and projecting without any expensive special lenses. The movie is produced in 1.375 format, and then the resulting image is simply cropped in post-production (or perhaps in the theater's projector) to fit the desired aspect ratio of 1.85:1 or 1.66:1 or whatever is desired. Besides costing less, the main advantage of the matte technique is that it leaves the studio with "real" footage (the areas that are cropped for the theatrical release) which can be used in preference to pan-and-scan when producing 4:3 DVD releases, for example.

The anamorphic encoding on DVD is related to the anamorphic filming technique (aka Cinemascope) only by name. For instance, Star Wars (1977) was filmed in 2.35:1 ratio using an anamorphic camera lens, and shown in theaters using the corresponding projector lens. Since it is a widescreen film, when encoded on a widescreen-format DVD the studio would almost certainly use the anamorphic encoding process. Monty Python and the Holy Grail was filmed in 1.85:1 ratio without using an anamorphic lens on the camera, and similarly was shown in theaters without the need for the decompression lens. However, since it is also a widescreen film, when encoded on a widescreen-format DVD the studio would probably use the anamorphic encoding process.

It doesn't matter whether the filming was done using the anamorphic lens technique: as long as the source footage is intended to be widescreen, the digital anamorphic encoding procedure is appropriate for the DVD release. As a sidenote, if a purely non-widescreen version of the analog-anamorphic Star Wars were to be released on DVD, the only options would be pan-and-scan or hardcoded 4:3 letterboxing (with the black letterboxes actually encoded as part of the DVD data). If you were to release a purely non-widescreen version of Monty Python, you would have those options, as well as the additional option of an "open-matte" release, where the film footage that was never visible in theaters (due to use of the matte technique in post-production or in the theatrical projectors) is "restored" to the purely non-widescreen DVD release.