The Wide-Screen Maze
Internet Filmmakers' FAQ
One of the most common areas of confusion for independent filmmakers working with digital video is in the area of wide-screen. In many cases, filmmakers want their movies to be seen in a wide-screen format, more akin to what we're used to with film, rather than the more square aspect ratio (4:3) found in television.
Many cameras, particularly the prosumer DV models, claim to have the ability to shoot wide-screen (sometimes called 16:9), however this can be misleading because not all cameras are able to do true wide-screen photography. Generally wide-screen photography for digital video is handled in one of three ways:
Most home camcorders and prosumer DV cameras (like the VX-1000, XL-1 etc) do wide-screen in Letterboxed format. Letterboxing is achieved by shooting a standard 4:3 picture and putting black borders on the top and bottom of the frame to create a picture shape that is the correct aspect ratio for the wide-screen required. This is not true wide-screen, and you are effectively wasting the black space in your image, effectively reducing the vertical resolution of your frame. The black borders are simply black video being recorded on the top and bottom of the frame! This will most likely cause you huge problems in post-production so it is best not to use in-camera wide-screen functions if your camera only shoots letterboxed format.
If you're going to use letterbox later down the track, frame you shots taking into account the future position of the black borders, but add them in post-production where you have more control.
Anamorphic is a method by which you can get true wide-screen images using a standard 4:3 camera. It is achieved by playing with the optics of the lens - anamorphic lenses use the optics in the glass to stretch the wide-screen image vertically and squish it horizontally so that it will fit into the 4:3 ratio. At the playback end (i.e. VTR, projector etc), a complimentary lens (or digital process) is used to return the image to its original aspect ratio.
Getting your head around the concept of anamorphic photography can be a little difficult to start with. Mark Anand provided the following basic example on the Shooting People filmmaker's mailing list: "If you imagine shooting a completely round object like a clock face. If you shoot in 4:3 and play it back the picture will look perfectly round. Now shoot the same clock in wide-screen Anamorphic and play that back on a 4:3 monitor - that same clock will look oval. Like the top and bottom had been stretched up and the left and right had been pushed in. Now take that same image and play it on a wide-screen monitor and that clock will again look perfect."
Obviously this is not a technical explanation, so if you are interested in learning more you should get your hands on a good book about cinematography. However, hopefully it illustrates the point.
Shooting anamorphic is probably the best way for independent filmmakers using DV to achieve a wide-screen result (particularly if you are planning to blow up to 35mm) because you are recording at the full vertical resolution of your camera (the exact resolution differs depending on whether you are shooting PAL or NTSC). You can get anamorphic adaptors and lenses for many of the prosumer DV cameras such as the XL-1, although they are not cheap to buy/hire.
True Wide-Screen Photography
The third way to achieve wide-screen is to use a camera has a rectangular CCD (rather than a squareish 4:3 CCD). Generally rectangular CCDs are only found in more expensive professional cameras such as those in Sony's DVCAM range and hi-def gear, although over time these may start appearing in prosumer equipment as well.
Check out A Quick Guide to Digital Video Resolution and Aspect Ratio Conversions; and British filmmaker Michael Askin also has some information on aspect ratio conversions wit Adobe Premiere at his site.