 |
-------------------------------------------------------------- This story was printed from CNET Asia. --------------------------------------------------------------
|
CNET's quick guide to HD camcorders
By Lori Grunin, CNET.com
Feb 05, 2007 URL: http://asia.cnet.com/hd-world/0,3800011581,61987306,00.htm If format proliferation is the sign of growing pains in a market, camcorders are in adolescent hell. Prices are dropping, making HD camcorders an attractive buy relative to their SD competitors, but inexpensive doesn't necessarily mean easy. Our most recent tally indicates there are no fewer than four possible media types to use, each of which can support multiple encoding formats; the encoding formats, in turn, support various combinations of standard-definition (SD) and high-definition (HD) video formats.Toss in HD's three different available resolutions, and you have an ugly mess to sort through while you shop. And we haven't even begun to see the inevitable models based on HD-DVD or Blu-ray discs.  Four myths about HD camcordersBefore you buy, check your expectations against reality. Standard-definition (SD) TV frequently acted as the great leveler with respect to video quality; it could make bad footage look better and great footage look bad. HDTV's more faithful reproduction capabilities place heavier demands on the capture device's resolution and color capacity, mercilessly rendering every blemish in flawed content but allowing the good stuff to really shine. So, here are five myths to keep in mind before you jump on the HD camcorder bandwagon.Myth #1: HD camcorder video is higher quality than SD. If the only determinant of quality were resolution, this might be true. But, as with digital cameras, it takes a lot more than just sheer numbers of pixels to produce a good picture. The lens, the dynamic range of the sensor(s), and the image processing and compression algorithms can be far more important. Myth #2: An HD camcorder complements HDTV better than an SD model. Don't confuse the resolution component of HD with its aspect ratio. Almost any camcorder these days can record wide-screen video if you simply want to fill up that 16:9 flat panel. Myth #3: If they cost the same, an HD model is a more future-proof choice than an SD model. As the clash between Blu-ray and HD-DVD illustrates, being cutting edge does not insure against obsolescence, even in the short run. Furthermore, the only real way to stave off the future is to opt for the best video quality you can afford--you're less likely to become disenchanted with a great camcorder than a model bought because it was last year's media darling. Myth #4: If it's not HD, it's not cutting edge. Plenty of technological change is happening in the camcorder category without limiting yourself to HD. A small and stylish chassis, the ability to record on flash media, and great still photography capabilities will all preserve your gadget mojo. HD recording formats: 720p or 1080iSo what's the difference between 720p and 10780i? The short answer is that they both look great, and most people have a hard time telling the difference. Here's the medium-size answer: The numbers 720 and 1080 refer to horizontal pixel counts, while the letters p and i refer to the picture-scanning method--either progressive or interlaced. (David Katzmaier, CNET.com)
HD recording formats: 720p and 1080iProponents of 1080i HD will tell you they offer the most lines of resolution, which is true. However, 1080i images are interlaced, meaning a tube TV draws the picture in two passes: Once for the odd-numbered lines, and again for the even-numbered lines. For 720p, or progressive, broadcasts, tube TVs draw each frame in a single pass, making for a smoother picture (nontube televisions display everything as progressive scan). While most viewers probably won't be able to tell the difference, videophiles tend to prefer the smoother images of 720p. (David Katzmaier, CNET.com)
Need to knowIn 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. But as you'd expect, there are some issues specific to HD to keep in mind as well.CCD aspect ratio and resolutionThough 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 outputThe 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.TapesYou 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. |
||||||||||||||||||||||||||||||||||||||||||||||||||||
Copyright © 2009 CBS Interactive Inc. All rights reserved. Privacy Policy.
