High Definition

High definition is here. With
more people purchasing HDTVs every day, it’s natural that they want to
begin capturing their holidays, school plays, and sporting events in
HD, as well. It’s tricky to know how to go about picking the right
camcorder, however.

Start with common sense. If an HD camcorder’s cheap price seems too
good to be true, there’s a reason. It’s easy to make a product that
meets all the technical requirements to be labelled “high definition.”
But a £150 HD camcorder will not make your football match look
like Spielberg. Expect that prices will be roughly commensurate with
quality.

The second thing to know is the difference between the two major types
of HD video. The first is 1280 × 720, typically abbreviated to 720P.
This means the resolution, or detail, of the frame is 1280 columns and
720 rows of pixels. The “P” is short for progressive, meaning the entire image is refreshed at a rate of 25 times per second, hence 720/25P.

The alternative resolution is 1920 × 1080, usually referred to as
1080i. If you’re catching on, you rightly guessed that the image is
sharper in 1080i because there are 1920 columns and 1080 rows of
pixels. However, that doesn’t mean that 1080 is definitively better
than 720. The “i” in 1080i stands for interlaced. If you break
the pixel rows up into evens and odds, imagine every odd row
refreshing, then every even row refreshing, then the odds, then evens,
and so on. Each of these fields refreshes 25 times per second, so the entire image is being partially refreshed 50 times per second, hence 1080/50i.



There is a third wave of technology that uses the larger 1920 × 1080 frame and
a full refresh rate of 50 frames per second (1080/50P). You’ve probably
seen lots of HDTVs touting this spec, because it’s fairly easy to
achieve on image display devices. But on the image acquisition side of
the equation, it’s mostly limited to expensive professional camcorders.


Buying an HD camcorder
Every camcorder manufacturer makes HD camcorders. Some record in 1080i,
some in 720P, and some in the rare 1080P. HD video can be recorded to
any recording media – tape, DVD, hard drive, memory card, or internal flash memory. The media is independent of the format, which refers to how the video has been encoded.

Formats are tricky. You can always plug your camcorder into your TV for
simple viewing, but if you want to edit video, the formats need to be
friendly with your computer software. The hope is that your computer
can take whatever you throw at it, but it’s not always that simple.
Here’s a quick run-down of formats that will at least familiarise you
with the terminology.

HDV is the oldest HD format, and is primarily limited to tape
camcorders. HDV is almost guaranteed to work with modern computers. Use
the FireWire connection (also known as IEEE 1394)

AVCHD is the most popular HD format for consumer camcorders,
shared between Sony, Panasonic, Canon, and JVC. Most internet forums
concerning video editing have lost, frustrated threads concerning
difficulties with AVCHD, but the problem has improved with time.
Originally, the issue was two-fold: a general lack of support from
software, and the processor-intensive nature of AVCHD files. The simple
passage of time has mitigated both issues. File transfer from camcorder
to computer uses USB.

MPEG-2 Transport Stream is now a minor figure in consumer video, as its champion, JVC, has adopted AVCHD.

AVC/H.264 MPEG-4 is known by a few names, but if your format is
not one of the three above, it’s probably in this category. There’s
nothing notably better or worse about H.264, it’s simply employed less
frequently by major camcorder manufacturers. You’ll see it most often
in Samsungs and Sanyos, and a lot of the budget ultracompacts like
Flip, Kodak, and others. If you use a Mac, you’re in luck, as they
offer near perfect H.264 compatibility. PC users may have to hunt down
the correct driver.

That’s all you should need to get started. Good luck!