Understanding widscreen (16:9) mode

by Andrew Alexander
Published on Feb 13, 2004 12:00 AM



There are three implementations of the widescreen control in camcorders, and only one of them is "true" widescreen. The others are workaround solutions to support widescreen televisions. For the purposes of this article I'm going to confine my comments to the NTSC (North American and other) television format. PAL works the same way, it's just that the numbers are different.

1. Letterbox matte

The simplest form of widescreen implementation is to just slap a black bar on the top and bottom of the recording area. A 720x405 image is recorded onto tape and when you play it back on a regular television, you see the letterboxed image. Whether or not it will play back properly on a widescreen television depends largely on the intelligence of the television. "Dumb" televisions require a special signal to tell the TV that it is receiving a widescreen signal, and will stretch the image appropriately; or, they require you to switch it manually. Smarter sets will analyze the signal it is receiving, and if it sees a letterboxed image, it will scale the image to fit. If the television is unable to figure it out, you will have an image that is letterboxed on all four sides!

2. Widescreen "stretch" mode

This form of widescreen mode is becoming a more popular way to implement the widescreen effect. The camcorder records the image as normal, but discards the top and bottom portions of the image where you'd expect to see letterbox bars, and stretches the image vertically to fit. In fact, this method produces an image of exactly the same quality as the letterbox matte method, but is usually more troublesome to deal with because most camcorders don't have a way to output letterboxed widescreen video on a regular 4:3 television. Rather, they output the stretched video they recorded, which looks too tall. On widescreen televisions, smart televisions will detect the widescreen signal and will stretch the image horizontally to make it fit the 16:9 aspect; for dumb televisions, they either don't, or you have to switch it manually.

3. True 16:9 camcorders

Widescreen mode in consumer camcorders is a software solution to the problem of adapting camcorders that shoot 4:3 aspect video to televisions which display 16:9. The real solution, of course, is to shoot video with a native 16:9 aspect ratio camcorder. These camcorders are not cheap, nor widely available, because only a small percentage of users have widescreen televisions, and with the inclusion of a widescreen mode, the manufacturers have 'technically' satisfied the demand to accomodate everybody.

So what's the best way?

The problem with shooting in a camcorder's widescreen mode is that you are depriving yourself of valuable screen resolution. You artificially remove around 16% of the vertical image, in an attempt to get more horizontal image. There are two 'better' ways around this problem, but none of them are really easy.

1. Anamorphic widescreen lens adapter

Depending on the model of your camcorder, you may be able to purchase a lens adapter which does the stretching of the image for you. With this adapter, you are recording an anamorphic widescreen image with every pixel of your camcorder's CCD, preserving the quality and getting a widescreen image as well. Companies like Optex and Century Optics make these adapters, but they're not cheap, in the realm of $500, and they only fit certain lens sizes.

2. Size correction in editing

For the money, the best solution is to shoot your project in regular 4:3 mode and edit it to a widescreen image in post-production. You may choose to make your shots a little wider, or actually use a guide in your viewfinder to show you what a 16:9 image would look like, but either way, after your project is shot you crop the image to a 16:9 resolution. Hollywood feature projects are shot with a 4:3 video market in mind, so there's no reason that you can't shoot 4:3 with a 16:9 product in mind.

Shooting in widescreen mode (preferrably letterbox) is one of many ways to give your product a film-like effect, however, it's important to remember that with widescreen mode, you're not expanding the image you're capturing in the horizontal plane; you're actually reducing the image you're capturing in the vertical plane. And, certainly, it looks great on a widescreen television. When it works!