Among folks who want to burn DVDs, the many
formats are the source of the most confusion. For starters, DVDs come in
two capacities: single-sided, 4.7 GB (almost seven times the capacity of a
CD, around 2 hours of high-quality audio and video) and double-sided, 9.4
GB (4 hours of audio and video, or as much as 16 hours at far lower
resolution). Here's the scoop on the five primary DVD formats:
1. DVD-R,
"DVD-Recordable" (read "DVD-dash-R"): write-once DVDs
similar to high-capacity CD-Rs. The main advantage of DVD-R is that it is
more widely playable on DVD players than other recordable DVD formats.
There are two types of DVD-R: DVD-R(G), or general, and DVD-R(A), or
authoring (professional). Consumer recording equipment requires DVD-R(G)
discs, though both types will play on most DVD players. DVD-R writes the
fastest in most drives (4x with applicable media), though newer "DVD
Multi" drives achieve speeds up to 8x with "dash" and
"plus" discs (see below). DVD-Rs must be finalized to be
readable in non-recording drives. In addition, multisession recording is
not allowed: DVD-R isn't merely write-once, but write at once.
2. DVD-RW,
"DVD-Rewriteable" (read "DVD-dash-RW"): similar in
concept to CD-RWs, only with far greater storage capacity. They're
rewriteable up to 1,000 times, and, like DVD-Rs, offer the widest
compatibility among existing DVD players and drives. Keep in mind,
however, that, unlike with data CD-RWs, you must rewrite an entire
DVD-RW to alter any data.
3. DVD+R
(read "DVD-plus-R"): a competing variant of the write-once DVD-R.
DVD+R media can sometimes be less expensive than DVD-R. It may also be
faster in some recorders and it is often more widely compatible with
existing hardware. But the real "plus" to the format lies in its
rewritable counterpart.
4. DVD+RW
(read "DVD-plus-RW"): initially less widely compatible than
DVD-RW, but now being supported by ever more DVD players. Significantly,
rewritable "plus" discs require no finalizing--you can record,
eject, and play them with minimal fuss, thanks to "background
formatting." This feature, which lowers total burning time, is an
advantage over the "dash" formats. For PC users, DVD+RW also
offers advantages over DVD-RW, including on-disc content editing, built-in
defect management, and multisession writing. DVD+RWs are designed for CAV
(constant angular velocity, as opposed to CLV, constant linear velocity)
recording, which, when CAV recorders become available, will be useful in
situations in which write speed and access time are essential. Be aware,
however, that rewritable "plus" discs cost much more than their
"dash" counterparts.
5. DVD-RAM,
"DVD Random Access Memory" (read "DVD-dash-RAM"): a
rewriteable format that uses Panasonic/Matsushita's phase-change dual (PD)
technology to offer superb access times, making it great for on-the-fly
data reading and writing, like a hard disk. Discs are pricey, however, and
compatibility low. Originally, DVD-RAM discs were available only in
special cartridges; now you can find them without the cartridges as well.
Many DVD-RAM drives require the cartridges, though. DVD-RAM discs are
reportedly good for writing up to 100,000 times.
6. DVD+R DL
(read "DVD-plus-R" Dual Layer): this technology dramatically
increases the storage capacity of burnable DVD media. DL media, when used
with a dual layer-compatible burner, offers up to 8.5 GB of storage
capacity. Keep in mind, though, that while DL media is advertised as
having 8.5 GB of capacity, they offer 7.95 GB of actual storage, due to
formatting and other factors. Dual layer media effectively doubles the
capacity of traditional DVD+R media, meaning you can store far more data
then ever before. The latest DVD+R DL drives can burn at up to 16X,
meaning you can burn a complete dual layer disc in about 15 minutes. Some
manufacturers are planning to release a DVD-R variant of dual layer media.
Because dual layer is a relatively new technology, be prepared to pay a
hefty premium for media.
7. Lightscribe Technology:
making labels for burned DVDs and CDs most often involves printing them
out on sticky paper and pasting them to the surface of the media.
Lightscribe technology may make that a thing of the past. When used in
conjunction with a compatible burner, special Lightscribe discs can be
laser-etched with lettering, designs and photos. When you're done burning
the data, you simply flip the disc over and "burn" the label
using a special laser-etching process. While Lightscribe does not offer
the ability to apply color designs to discs (Lightscribe labels resemble
sepia-toned photographs), the labeling is permanently applied to the
media, making it long-lasting and highly durable. Currently, HP is the
only manufacturer offering Lightscribe-enabled DVD and CD burners.
Compatible media is offered by HP, Memorex, Imation and Verbatim.
8. High Definition DVD Formats:
the big electronics and media companies have been developing the next
generation of DVD formats for awhile now. High definition content and
massive storage capacity will be the name of the game in the years to
come, and two formats, Blu-ray and HD-DVD are poised to enter our living
rooms. Just like the DVD vs. Betamax battles of old, though, consumers may
be faced with deciding which of the competing formats to go with. Both
technologies use new laser technology that crams far more data onto a
single disc, but Blue-ray may have the edge here, offering 50 GB of dual
layer capacity to DVD-HD's 30GB. However, HD-DVD media may be cheaper to
produce and may offer better backwards compatibility with conventional DVD
players. Japanese consumers have already been treated to single layer Blu-ray
player/recorders, which can record up to 4.5 hours of HD video on a single
disc.
With
more media types and format variants than ever before, it can be a
challenge to find the right recordable media for your purposes. This
buying guide is where you can learn the difference between DVD-RW and
DVD+RW, CD-R and CD-RW, and more.