Anamorphic widescreen is a technique that can be applied to both film recording and DVD authoring to get the best picture resolution possible. In filming, this method captures the motion picture image in a format where the entire film area is used. The image is sent through a specialized anamorphic lens during recording. This stretches the image to completely fill the film while recording. This is done with film cameras, most notably on those designed to be used with the standard 35mm film. This places all of the information from the widescreen format onto the film. When this film format is played back in a movie theater for instance, the image is passed through a filter, which then stretches out the video to the correct widescreen format once again.

In DVD authoring, the video information is compressed into a normal screen format that the DVD player or television being used for playback can adjust. The anamorphic widescreen format is often the best option for DVD in order to get the best video playback of the film. The DVD player or television can stretch the video or crop it to fit correctly for playback. This allows the best image with any television without having to purchase a specific DVD type for the player. A large majority of DVDs are produced with the anamorphic widescreen format.

The Development of Anamorphic Widescreen

Prior to the 1950s, widescreen format recording was done on normal 35mm. Although the film’s aspect ratio was preserved and the image fit on the screen, the black bars would be visible during playback. This is commonly known as “Letterboxing,” which preserves the original video in widescreen on the 35mm film. This could also be modified so that the bottom black bar was larger in order to place hard subtitles without having to overlap onto the image portion of the film.

Although this was not damaging the film picture when shown in theaters, when the format was converted to an aspect more suitable for home viewing (such as 4:3), a large portion of what is normally seen on the 35mm film was cropped out to remove the extra black bars from the top and bottom of the viewable area. Another problem with the widescreen format was that if it was not changed when made to fit the home screen, the video would be smaller.

As filming progresses with an anamorphic widescreen lens, the entire frame is stretched to fit onto the negative, distorting the image vertically by filling the entire film area. During playback of the footage, a special lens is required to correct the image distortion that occurs in a proportionate ratio. This incidentally increases the film’s resolution, thereby increasing picture quality when displayed on a variety of screen formats in the cinema.

The way anamorphic widescreen video functions for DVDs is fairly similar to that of the cinema. A conventional television screen would have an aspect ratio of 4:3 or 1.37:1 and would need to display the image data in an undistorted manner. The process to accommodate the image data required that the data is shown as is, without cropping, and the black bars on the top and bottom of the screen or the image are shown at the appropriate size, cropped to the appropriate aspect ratio for the screen size.

Anamorphic Widescreen DVD image data allows the vertically stretched data to be fit into the displayed frame proportionately on the television. Non-anamorphic widescreen DVDs are designed to have black bars already included in the image data and will not be stretched to the size of the television in some instances. The result is a picture that fits the screen but has the addition of black or gray bars on the left and right of the image because the data does not fill the screen correctly.

To find out whether or not a DVD provides an anamorphic widescreen video format, check the DVD label for “Anamorphic” or “enhanced for 16:9” mentions in the aspect ratio information.

Digital television broadcasts have also utilized the 16:9 since the year 2009 so that transmissions convert better to the modern television aspect ratios.

Widescreen Letterbox

Widescreen Letterbox is basically an option for widescreen formats of any size to be displayed within the constraints of the particular “screen.” For example, a 2.35:1 aspect widescreen image is much longer than a 1.33:1 screen. The 2.35:1 picture will be proportionately played at the width of the 1.33:1 screen, but the remaining height information will be filled with the black bars on the top and bottom of the picture.

Source Aspect Ratio

In both physical and digital film, the aspect ratio for the final image can be as high as necessary to convey to the destination “screen.” A DVD (or Bluray Disc) uses the source aspect ratio it is displaying in a pixel by pixel rendering of the source video. The advancements in the Bluray technology made it possible to get a variety of resolutions for video playback. The maximum possible with Bluray is 1920×1080 designed for 16:9 screen formats. Source aspect ratio works similar to anamorphic widescreen and can actually have the 1440×1080 resolution size for 16:9 aspect ratio anamorphic widescreen play back.