Posted by John S. Dyson on 10/14/05 23:33

In article <1129245906.060365.30090@z14g2000cwz.googlegroups.com>,
"Lansworth" <ptlansworth@gmail.com> writes:
> I couldn't phrase it better than what I put in my subject line, so I
> won't: SVHS -- Apparently Kicks VHS's butt, but how does it compare to
> others? I am aware it doesn't live up to formats like DVCAM, DVCPRO,
> etc. (thats a given), but does it produce a fairly decent image? I have
> heard it does have a fair amount of resolution, at about 400. Not
> excellent, but better than VHS. Thoughts? I want to hear what you have
> to say.
>
When comparing FORMATS it is important to also consider the
actual machine. I believe this to be especially true for the
consumer analog format SVHS.

Resolution isn't really the most important parameter of a recording
format. Alot of tradeoffs come along with resolution. For formats
like SVHS/VHS/etc, IMO the biggest gotcha is chroma performance of all
kinds.

Another big difference is the multi-generational performance. SVHS
doesnt' seem to hold up for very many generations, but D9 (a DV50
format) really does look about as good as BetaCamSP after more
than several generations. After several generations, SVHS will tend
to start looking 'not very good.' (I ran some tests on D9, where
I did 10 record/playback cycles through the component I/O ports, and
it stilly looked very good -- far beyond SVHS for the first generation.)

For an 'interesting' time, record a multi-burst on an SVHS deck, and
play it back without 3D noise reduction (but certainly with TBC enabled.)
You might notice defects in the high frequency reproduction. For
normal DV, you'll notice rock-solid reproduction. Then, make a third
generation copy of that multi-burst (using the appropriate copy settings
on the SVHS VCR), using SVideo I/O for both DV and SVHS. The comparison might
be interesting. For a stationary pattern, DV25 and DVHS will likely perform
similarly, while SVHS will tend (depending upon the deck) to look worse
than the original. Disclaimer: MULTIBURST is not a difficult test for
the typical digital formats like DV25 or DVHS MPEG. Movement (mostly
MPEG) or irregular detail are more difficult for those formats.

Given that comparison, then note that DV25 (normal DV) tends to be on the
low end of the SDTV quality scale -- but still pretty good. Formats
like DigiBeta will start diminishing to DV25 quality after 5-10record/playback
generations. (i.e. the fifth copy of a copy of a copy of a copy, etc.)


John

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