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Posted by Mike S. on 04/05/06 12:34
In article <e105nb$9v4$1@newsreader.mailgate.org>,
Darling <darling@nomail.com> wrote:
>Hello
>
>
>
>I'm looking for a LG DR7800 recorder. On manual I found it can record DVDs
>using four different quality levels: HQ, SQ, LQ and EQ. Maybe someone cal
>help me understand the difference of these quality levels compared with the
>quality level of a video tape? In particular, using the LQ quality level (4
>hours) I will have the same quality of a video tape or it will be lower?
>Then, can I play all recorder modes (HQ, SQ, LQ and EQ) on the other DVD
>players?
As a digital recorder squeezes more and more data onto a disc, compromises
are made in the "quality" of the recording. These amount to two things -
image resolution and what I call "temporal resolution".
After 2-hour mode, many DVD recorders start cutting down on the image
resolution, so there is loss of detail. Even at half resolution you are
better than VHS, so this is not a big issue. (Some of the newer Panasonic
recorders with the "Diga" circuitry even improve on this).
Almost all the modes that fit more than 1 hour on a disc will reduce
"temporal resolution". By that I mean the MPEG encoding is done at a lower
data rate, meaning there is less data available to encode "transitions" as
things move on the screen. So if you are recording things in which things
move slowly on the screen, the effect is minimal. If there is a lot of
detail AND movement (e.g. sports) then you start to see pixellization,
breakup, and other MPEG artifacts.
For most purposes, it is said that the modes which achieve 4 hour encoding
on a DVD will give acceptable results in transferring from VHS. If there
is any doubt, use the 2-hour mode which will give the same recording time
as a VHS tape in SP mode, and performance that's generally much better.
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