Date: Thu, 18 Nov 1999 14:29:41 +0000 (GMT) From: Jonathon McKitrick <jcm@dogma.freebsd-uk.eu.org> To: Craig Harding <crh@outpost.co.nz> Cc: Terry Lambert <tlambert@primenet.com>, chat@freebsd.org Subject: Re: Judge: "Gates Was Main Culprit" Message-ID: <Pine.BSF.4.02A.9911181427120.301-100000@dogma.freebsd-uk.eu.org> In-Reply-To: <19991118050528.7618214C0D@hub.freebsd.org>
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Since you seem to have a clear picture (pardon the pun) of this whole debate, could you explain whether the salient points from this discussion can support the premises we have been debating? Is it possible for company to cause the adoption of lesser technology purely by business/marketing tactics? What *really* was responsible for the success of BetaMax over VHS? On Thu, 18 Nov 1999, Craig Harding wrote: >Terry Lambert wrote: > >> Even ignoring this, the rotating record head is away from the >> tape media for longer than the vertical blanking interval, and >> that means that you get a 1.5 reduction in frame rate. This >> reduction in frame rate is even more noticible because of >> horizontal retrace in PAL vs. NTSC. >> >> The result is that the 525 lines of vertical resolution are reduced >> to 200 for VHS, 400 for SuperVHS > >Erm, actually I think you're getting a couple of things confused here >Terry. > >Firstly, I don't know what you're trying to say about frame rate, as >far as I'm aware PAL video runs at 50 fields (25 frames) per second >and NTSC runs at 60 fields (30 frames) per second [1]. > >As for resolution, you've been confused by the terminology. PAL >always displays (approximately) 625 scanlines on the screen, and >NTSC always shows 525. That's actual horizontal scans by the >electron gun across the width of the screen, half in each interlaced >field. > >When we talk about the resolution of a tape format (or a camera or >monitor) in video circles, we're referring to the horizontal >resolution, which is loosely equivalent to the frequency response of >the intensity signal of the electron beam as it sweeps across the >display. > >The resolution is measured by the only handy unit available in >pre-computer display times - screen lines. So we're talking about >resolution in terms of roughly square notional pixels, which means we >use the size of vertical screen lines to talk about horizontal >resolution. > >Some camera test charts actually have a resolution grid on them, with >horizontal and vertical lines drawn in an increasingly-finer >gradient. When you can no longer distinguish individual lines, you've >hit the resolution limit of the camera (or monitor, or whatever). > >VHS, as Terry mentioned, has about 200-240 lines resolution. Super >VHS has theoretically close to 500, where as the broadcast >format BetaSP is only 450. This leads some people to claim that Super >VHS is superior to BetaSP because they are ignoring SVHS's terrible >colour resolution. > >Modern broadcast video cameras have a horizontal resolution of about >850 lines. >-- >Craig Harding crh@outpost.co.nz "I don't know about God, I >Outpost Digital Media Ltd crh@inspire.net.nz just think we're handmade" >http://www.outpost.co.nz ICQ# 26701833 - Polly > > >To Unsubscribe: send mail to majordomo@FreeBSD.org >with "unsubscribe freebsd-chat" in the body of the message > -jonathon To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-chat" in the body of the message
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