Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!water!watnot!watmath!clyde!rutgers!ames!ucbcad!ucbvax!decvax!tektronix!tekcrl!vice!tekfdi!videovax!stever From: stever@videovax.UUCP Newsgroups: comp.sys.amiga Subject: Re: new amiga computers Message-ID: <4244@videovax.Tek.COM> Date: Mon, 23-Feb-87 11:42:35 EST Article-I.D.: videovax.4244 Posted: Mon Feb 23 11:42:35 1987 Date-Received: Fri, 27-Feb-87 00:25:36 EST References: <4047@utcsri.UUCP> <479@linus.UUCP> <1391@cadovax.UUCP> <126@toylnd.UUCP> <1272@husc6.UUCP> Reply-To: stever@videovax.Tek.COM (Steven E. Rice, P.E.) Organization: Tektronix Television Systems, Beaverton, Oregon Lines: 29 Summary: Interlace v. progressive scan comparisons are not simple. . . In article <1272@husc6.UUCP>, Mitsuharu Hadeishi (hadeishi@husc4.UUCP) writes: > . . . > Also, there is a fantastically good reason why you'd want to > keep the interlace mode on any future Amiga; with interlace you can get > twice the vertical resolution without any loss of bandwidth. . . . Unfortunately, there is a price to be paid for interlacing a display. Part of the price is a reduction in vertical resolution from the theoretical maximum. The Kell Factor (named after the gentleman who first described the phenomenon) is typically in the range of 0.6 to 0.7 for 2:1 interlaced displays. Thus, interlace provides a 20% to 40% improvement in vertical resolution when compared to a progressively-scanned display which has half the number of lines per frame. A problem with interlaced displays is that some patterns will have a flicker frequency that is half the field rate. While your eyes are not particularly sensitive to 60 Hz flicker, they certainly are sensitive to 30 Hz flicker! Try an experiment -- first, fill a non-interlaced screen with "E" (the capital letter). Then, fill an interlaced screen with "E" (be sure to use a font that has a single row of dots for the horizontal lines). Which one has more flicker? Steve Rice ---------------------------------------------------------------------------- {decvax | hplabs | ihnp4 | uw-beaver}!tektronix!videovax!stever