So if you can link your SD camcorder to your regular TV, what's the big deal with HD versions? Lots of pixels, for one thing — three times as many pixels as the best offered by National Television System Committee (NTSC) versions, encoded as a standard MPEG-2 stream.
Ever wonder why the SD camcorders look so poor on your HDTV? It's simply a reflection of the lower resolution of the SD stream when scaled up and viewed on your HD screen — the two were simply not meant for each other.
But lots of pixels mean lots of megabytes, too. An uncompressed 1280 x 720 BMP file can be almost 3MB in size — that's just a single frame of video (1/30 or 1/60 of a second's worth of video). That's the price of high-definition.
Of course, HD camcorders use a ton of computer horsepower to compress these video frames so that they use less storage space — but HDTV video still uses a ton!
High-def camcorders have the following two main competing standards:
- HDV: HDV (high-definition video) camcorders use the same DV format as MiniDV standard-definition camcorders, but the DV encoding format used by those camcorders is thrown away and replaced by good old MPEG-2. MPEG-2 allows the camcorder to put a lot more data on the same tape, and it provides support for both 720p and 1080i HDTV formats. Most HDV camcorders record in one format or the other, however, so when you shop for an HDV camcorder, you must choose 720p or 1080i. Note that some HDV camcorders can forego the tape and record directly to a hard drive. The biggest advantage of HDV (besides the fact that it uses the tried-and-true MiniDV tape format) is that you can easily edit the video it produces on PCs. Many Windows programs can support HDV editing, and all Macs with Apple's iMovie can edit HDV out of the box.
- AVCHD: A newer format for HD camcorders is AVCHD (Advanced Video Codec High Definition). AVCHD uses the MPEG-4 encoding system, which is more efficient than MPEG-2 and is often called MPEG-4 AVC, hence the AVCHD name. AVCHD camcorders typically use small recordable DVDs as their storage media, just like DVD standard-definition camcorders. However, they can also use internal hard drives or flash memory systems to record their 720p or 1080i video. AVCHD camcorders are usually nice and compact because they don't need the bulky tape-handling mechanism, but they typically can't hold quite as much video as a tape-based machine, and the MPEG-4 video (plus the DVD format) isn't as easily transferred to and edited on a computer.
You can play the DVDs recorded by AVCHD camcorders in a Blu-ray disc player (or Sony PlayStation 3, which has a built-in Blu-ray disc player). Note that these discs don't play in an HD DVD player.
You can also find some proprietary HDTV camcorders, which use neither of these formats but instead use some vendor-specific system. For example, Sanyo's Xacti VPC-HD1 camcorder records 720p video by using MPEG-4 compression and saving the video onto flash memory, but it doesn't use AVCHD. Rather, it uses Sanyo's own system for such recordings.
When dealing with the higher resolution and more detailed image of a high-definition camcorder movie and its display, everything is more noticeable. Errors such as shaky handheld shots, too much panning, and zooming too fast can make people dizzy (if not nauseated) when viewed on a large display. Think about using a tripod or bracing yourself more securely when making videos.
Other than the resolution, much of the camcorder will look familiar to you — expect the same high-speed interfaces (such as FireWire) and even the same tape formats (in the case of HDV).
dummies
Source:http://www.dummies.com/how-to/content/hdtv-insights-introducing-highdefinition-camcorder.html
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