On Mon, 31 Dec 2001 19:30:37 GMT, Loren Amelang
>On Mon, 31 Dec 2001 14:32:21 GMT, d_ruether@hotmail.com
>(Neuman - Ruether) wrote:
>> On Sun, 30 Dec 2001 23:36:31 -0500, "Clay Schneider"
>>
>> >"Neuman - Ruether"
>message news:3c30e302.43932451@newsstand.cit.cornell.edu...
>> >> As I understand it, the Canon does reduce resolution
>in the
>> >> process of making full-frame-rate PS-mode video
>> >not sure what would make you think that.
>> This has often been reported - it has something to do
>> with not having true progressive-scan at 1/30th second,
>> resulting in a need for interpolation, as I recall...
>The best explanation I have seen is here:
>http://www.dv.com/magazine/2000/1100/wilt1100.html
>It includes diagrams of exactly which pixels are averaged to
>produce the illusion of progressive scan, and resolution
>chart samples. No DV camera I know of outputs raw pixels
>one-for-one in any mode anyway, so this is just one more bit
>of DSP software between the lens and the tape. Most DV
>cameras have more green pixels than red or blue (hence
>the preference for green-screen over blue-screen keying),
>so averaging the greens may not be as big a loss as it might
>seem.
>
>As for getting PS-captured DV data through the interlaced
>format tape and onto a PS monitor looking better than if it
>was captured in interlaced mode, it is not likely today. I
>suppose someday there might be DSP code in the monitor
>that could recognize the lack of interlace artifacts between
>the two fields of each frame, and process that video stream
>differently - sort of like some systems now recognize that a
>video stream has been subjected to 3:2 pulldown and
>remake each output frame accordingly in real time. But I
>haven't heard of anyone trying it.
>
>Loren
Thanks for an interesting and informative post.