The popularity of DVD has brought about a whole new range of questions involving system set-up, not just in terms of audio but video as well. Unlike the vast majority of laserdisc players and all video cassette recorders, the way one configures the video output will affect the picture quality you see, and this also depends upon the features of your monitor or projection system.
Anamorphic DVD-Video Explained
Firstly, the use of at least the Y/C connections (S-Video) is important - DVD stores the chrominance (colour) and luminance (black and white) picture elements separately and using the Y/C interface removes the need to combine these elements within the player then separate them again in the TV or projector (as happens when using a composite connection). Component connections are better still, transmitting the colour elements separately. Players intended for PAL regions will have RGB connections in the place of the component ones found in NTSC territories.
The most important playback element, apart from the above, revolves around playback of DVD-Video discs which are "Enhanced for 16:9 TVs". "16:9" is an expression of the television or screen ratio - sixteen elements wide and nine elements high. These "elements" can be inches, feet or any other unit of measurement. "Standard" televisions have a screen ratio which is 4:3 (four elements wide, three elements high).
Figure 1: A letterbox picture upon a 4:3 ratio screen
NTSC television has 525 lines of horizontal resolution, so when playing a movie which is "Letterbox" or "Widescreen", in order to show the entire width of the picture, horizontal black bars appear above and below the image. These black bars themselves use some of the horizontal scanning lines, therefore the actual picture is made up of considerably less than 525 horizontal lines. See Figure 1 to the right, it is a representation of a letterbox image (with a ratio of 16:9) shown upon a 4:3 television.
If one has a 16:9 "Widescreen" television or projector, this image is then increased in size to fill the entire screen. Gone are the black bars top and bottom (depending on the ratio of the image, PanaVision titles can still have black bars due to their extreme width in comparison to their height) but the resolution remains the same, the picture has the same number of horizontal lines as it would on a 4:3 television.
Figure 2: An "Enhanced" anamorphic picture upon a 4:3 ratio screen
"Enhanced" DVD-Video discs contain images which have been 'expanded' along the vertical plane. When viewed upon a 4:3 television or projector, this makes the image appear to be too tall and thin although it fills the entire screen - there are no black bars top and bottom as before.
What is needed is something to correct this distortion - in other words - to reverse the expansion of the image. To the right (Figure 2) is a representation of an "Enhanced" (anamorphic) image seen upon a 4:3 television or projector. Note that the picture appears to be unnaturally tall and thin but there are no black bars visible.
Figure 3: An "Enhanced" anamorphic picture corrected to fill a 16:9 ratio screen
Many modern "Widescreen" 16:9 televisions and projectors have viewing modes which enable the user to correct the ratio of the image. Just as the image was expanded along the vertical plane when recording it to disc, the television or projector now reduces the picture along the same plane (equivalent to compressing it along the vertical plane). Exactly the same, but opposite amount of distortion is added and this counteracts the geometric irregularity. What results is a 16:9 image which is the same width and height as before, but is made up from the entire 525 horizontal scanning lines available. When viewed correctly, the image is clearly of higher definition. Figure 3 shows this image upon a 16:9 screen. Note that the screen is the same height as the 4:3 example as it has the same horizontal resolution, but it is wider and no black bars at the top and bottom are visible.
"What happens if I haven't got a widescreen television or projector, will 'Enhanced' discs look funny?"
No, not unless you're the clue-less editor of an A/V magazine. All DVD players give you the option to select your preferred screen ratio. If you select 4:3, "Enhanced" images will be corrected within the player and appear as normal letterbox laserdiscs or videos - remember though that the image resolution will be the same as that from non-"Enhanced" discs. Selecting 16:9 as your display option within the DVD player's menu will allow one to take full advantage of the performance provided by "Enhanced" discs, and this together with a Y/C or Component connection and a carefully calibrated system (Video Essentials is a good choice) will provide the stunning picture quality of which DVD-Video is capable.
Lastly, when planning a movie night at home, it's important to consider the overall entertainment experience. While anamorphic DVDs can greatly enhance the picture quality, don't forget the comfort of your own viewing environment. Investing in a cozy seating arrangement, proper sound system, and a darkened room can truly elevate your home theater experience to the level of a luxury hotel.