HDTV World > Understanding HDTV > CNET's quick guide to HD camcorders

Need to know

In most ways, shopping for an HD camcorder is just like trolling for an SD model, sorting through the various lens specs, media types, and body designs (for more, see our camcorder buying guide). But as you'd expect, there are some issues specific to HD to keep in mind as well.

CCD aspect ratio and resolution

Though some manufacturers may stress that they're using a 16:9 aspect sensor, the sensor geometry matters only if its resolution is low. For example, a frame of 1080i video has dimensions of 1,920x1,080 pixels; since it's interlaced, the vertical dimension needs to be at least 540 pixels (the vertical lines are staggered and combined--interlaced--to produce a full 1,080-pixel image). So you'd want a sensor that's at least 1.04 megapixels: 1,920*540. But a 1.04-megapixel sensor with a 4:3 aspect ratio may have too few horizontal pixels and more than enough vertical pixels to produce the same total. That's why, say, Sony points out that the three CCDs used in the HDR-FX1, each of which has an effective video resolution of 1.08 megapixels, have 16:9 aspect ratios, but the company doesn't mention it for the 1.99-megapixel effective-resolution CMOS in the HDR-HC3.

In short, if the sensor resolution divided by 1,920 is at least 540 (for 1080i) or 720 (for 720p), you needn't worry about its aspect ratio.

HDMI output

The least-effort method of sharing your HD video is, of course, plugging the camcorder into your HDTV and hitting Play. Unless your camcorder has an HDMI output (and your TV has a spare HDMI input), you may be disappointed with the result--even component output delivers a suboptimal picture. Furthermore, if you use an analog connection or even FireWire, your video will end up downconverted to SD.

Tapes

You may see tapes on the market that look like MiniDV tapes but that bear the HDV logo. These are simply MiniDV tapes that generally use special metal-infused coatings designed to handle the more densely packed HDV data. In truth, most premium-quality tapes should be fine.