Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!samsung!umich!terminator!msiskin
From: msiskin@css.itd.umich.edu (Marc Siskin)
Newsgroups: comp.sys.amiga.graphics
Subject: Re: term \
Message-ID: <1991Apr29.191359.20714@terminator.cc.umich.edu>
Date: 29 Apr 91 19:13:59 GMT
References: <8910@crash.cts.com>
Sender: usenet@terminator.cc.umich.edu (usenet news)
Organization: Univ. of Michigan Language Lba Video Services
Lines: 47

In article <8910@crash.cts.com> seanc@pro-party.cts.com (Sean Cunningham) writes:
>In-Reply-To: message from dltaylor@cns.SanDiego.NCR.COM
>
>I enjoyed your message, but felt that I must make a correction with regards
>to your claims on NTSC video.

And I to your claims....
> 
>NTSC has 525 horizontal scanlines, of which, 480 +/- 3 are actually used
                                              504  +/- are used (525.5 - 21 
lines for sync information.  The 480 lines you refer to are the best
resolution (not number of lines) you normally get from Broadcast TV.  
Resolution is how well you can resolve closely spaced black and white lines.
the Higher the Number the more lines per unit (not sure  which unit they use)
you can see.  Resolution is limited by the high frequency componant of the
signal.  The higher the frequency, the more lines of resolution possible.

 
>For video gear, 400 lines of resolution or better is needed to be
>considered broadcast quality...even though the extra resolution is never
>broadcast, it helps during the editing process where one or more dubs may
>be used.

Good point here.  The higher the resolution before the degradation of 
transmission the better looking the picture on the TV (not monitor).  
Look at pictures recorded by TV Newscrews and those shot by home camcorders
and you will see a difference.  The TV stuff will look sharper because they
are recording more resolution information than the camcorder does.  Also
try looking closely at a still image of a VHS tape.  You should notice that
there is a LOT of noise that you can see in pause that you can't see in
motion.  The home formats take advantage of the randomness of noise and 
the fact that the human eye doesn't retain images very long.  

> 
>Sean
>
> 
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> .SIG v2.5 <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
>  UUCP: ...!crash!pnet01!pro-party!seanc       RealWorld: Sean Cunningham

Marc Siskin, Senior Media Designer and Video Engineer for the Language Lab
at the University of Michigan.

std. Disclaimer.
Msiskin@shogun.css.itd.umich.edu
Marc_Siskin@ub.cc.umich.edu
userHEBE@umichub.bitnet