David Pogue has an interesting article in the NY Times today:
Thursday, November 20, 2003
'Tis the Season of the DVD
Man, if I were a VCR, I'd be nervous right about now. If the Pioneer
DVD-burning TiVo that I reviewed last week is any indication, the
videotape era is almost over.
As prices of set-top DVD recorders drop into the sub-$400 range, more
people than ever will be buying them, not just to record TV shows, but
also to rescue their old home movies. At this very moment, VHS and 8mm
tapes from the 80's are beginning to disintegrate in their boxes.
Most people assume that the DVD is the perfect way to save those
tapes. After all, a DVD has so many advantages over tape:
• You can skip around almost instantaneously using the DVD player's
remote control. (No one ever had to pay Blockbuster for not rewinding a
• DVD's are compact. A wall-unit shelf can hold a heck of a lot more
DVD's than VHS tapes, and mailing a home-movie DVD to relatives is a
heck of a lot cheaper.
• DVD's last a lot longer than VHS tapes, which begin to deteriorate
in 10 or 15 years.
• DVD's have much better quality than VHS tape — 500 lines of
resolution, as opposed to 240.
Yes, that's is what people assume — but DVD recording isn't all that
it may seem.
As you launch yourself into the uniquely 2003 project of transferring
your old videos onto DVD's, keep a few points in mind.
First of all, this business about DVD's being a permanent medium, one
that your heirs will enjoy watching with their heirs, is entirely
unproven. Truth is, nobody can really say how long DVD's last. They're
too new, and the quality of blanks is too variable.
After all, we're not even talking about "real" DVD's, the ones that
Hollywood puts out. Home DVD burners don't actually "press" discs,
embedding tiny encoded textures into the plastic itself, as commercial
DVD plants do; instead, they change the patterns in a layer of dye on
the disc surface. That kind of DVD's longevity is still a big question
Remember, too, that discs you burn yourself (DVD-R, DVD+R, DVD-RW, and
so on) don't work in as many standard DVD players as commercially
pressed discs. Before you mail out a DVD of your latest home-video
opus, check the master player compatibility list at www.dvdrhelp.com to
find out if your recipient will even be able to play it.
And one more thing. When you transfer an analog tape (VHS or 8mm) to a
DVD, you probably won't lose much video quality. Indeed, some DVD
recorders even have picture-enhancement circuitry.
But transferring movies from a modern digital camcorder is another
story. Video on a DVD is actually compressed (using so-called MPEG-2
encoding), meaning that you actually lose some of the video data that
was present on the original camcorder tapes.
The amount of quality loss depends on the degree of compression. Most
DVD recorders can burn a DVD so that it holds one, two, four or six
hours of video, with increasing amounts of compression (and
deterioration of quality). At the one-hour setting, you probably won't
see any difference between your original digital tape and a homemade
Still, if you're burning a DVD of some particularly priceless piece of
footage, consider keeping the master Mini-DV cassette, so that you'll
always have the original, pristine video available.
(So how can Hollywood fit a two- or three-hour movie on a DVD at
terrific quality? Because its commercial DVD-recording equipment can do
something that home burners can't do: variable bit-rate encoding. That
is, their computers analyze every frame of an entire movie before
burning it — a time-consuming process — and, when creating the DVD,
adjusting the amount of data required to render each scene depending on
what's in it. Home DVD recorders don't bother. They use the same high
data rate — say, five or eight megabits per second — for the entire
length of the video, so you don't get as much video on a disc.)
None of this is to dispute that home DVD recording is the greatest
thing since sliced bread. Transferring old videos to discs still
confers sure-fire benefits; just be sure you know which ones they are.