Mattes and Widescreen Filming
Another use of mattes in filmmaking is to create a widescreen effect. In this process, the top and bottom of a standard frame are matted out, or masked, with black bars, i.e. the film print has a thick frame line. Then the frame within the full frame is enlarged to fill a screen when projected in a theater.
Thus, in "masked widescreen" an image with an aspect ratio of 1.85:1 is created by using a standard, 1.37:1 frame and matting out the top and bottom. If the image is matted during the filming process it is called a hard matte due to its sharp edge. In contrast, if the full frame is filled during filming and the projectionist is relied upon to matte out the top and bottom in the theater, it is referred to as a soft matte, as the aperture plate is not on the focal plane and causes a soft edge.
In video, a similar effect is often used to present widescreen films on a conventional, 1.33:1 television screen. In this case, the process is called letterboxing. However, in letterboxing, the top and bottom of the actual image are not matted out. The picture is "pushed" farther back on screen and thus made "smaller", so to speak, so that, in a widescreen film, the viewer can see, on the left and right of the picture, what would normally be omitted if the film were shown fullscreen on television, achieving a sort of "widescreen" effect on a square TV screen. In letterboxing, the top of the image is slightly lower than usual, the bottom is higher, and the unused portion of the screen is covered by black bars. For video transfers, transferring a "soft matte" film to a home video format with the full frame exposed, thus removing the mattes at the top and bottom, is referred to as an "open matte transfer." In contrast, transferring a "soft matte" film to a home video format with the theatrical mattes intact is referred to as a "closed matte transfer."
Read more about this topic: Matte (filmmaking)