"Ralfe Cookson" <ralfe.cookson@trw.com> wrote in message

news:6085b684.0309050657.501d0aec@posting.google.com...

> bigrocketman3@webtv.net (Steve McDonald) wrote in message

news:<6366-3F5712C2-32@storefull-2118.public.lawson.webtv.net>...

> > For those who didn't read David Reuther's reply carefully, I

> > reiterate: All the active video pixels on a MegaPixel CCD contribute to

> > the generation of an analog waveform signal that carries the image to

> > the digital converter and then to digital tape. The extra CCD pixels

> > help generate an improved analog signal that can allow for an all-around

> > better digital picture to be derived from it. None of the individual

> > analog CCD pixel responses are converted directly to individual digital

> > pixels. You can't accurately calculate that a MegaPixel camcorder will

> > allow a digital picture to be produced that is 19% sharper than that of

> > a non-MegaPixel model, based just on the number of extra CCD pixels.

> > The resolution tests that have been conducted by video engineers, show

> > that playback resolution from a TRV730 is close to 500 horizontal lines,

> > while that of any of the Sony non-MegaPixel Digital8 models is about 350

> > lines.

> >

> > The biggest problem with these Sony non-MegaPixel Digital8 models,

> > is that they don't have enough active pixels to generate a good enough

> > analog signal to produce more than 350 lines of resolution in digital

> > form.

> If this is true, can you explain why it is that the Sony DCR VX2000

> and PD150 "professional" model camcorders have CCDs with only 380K

> pixels? Is the image produced by these camcorders not as good as that

> of the consumer level megapixel CCD models? My impression is that the

> VX2000 and PD150 produce very good "broadcast quality" images and all

> the megapixel CCD garbage is just a bunch of useless bells and

> whistles so marketing people can say their camcorders can take still

> photos, at the cost of reducing motion video quality.

As we have been pointing out, the megapixel+ models of 1-CCD cameras

do have improved image sharpness and color compared with lower

pixel-count models (though there can be downsides, such as more

motion-artifacting and lessened low-light range with the higher pixel-count

models). As for the 3-CCD models, they have a total pixel count that

is 3X the count for any one of the three CCDs used, giving a rather high

total. As SMcD points out, the effect is evident in the higher quality of

the stills, even though the image pixel size is lower compared with the

megapixel 1-CCD models. This 3-CCD advantage can also be seen when

comparing motion-video...