On Mon, 13 May 2002 13:49:14 -0700 (PDT), bigrocketman3@webtv.net (Steve McDonald) wrote:

> The CCD image-sensors on camcorders produce an analog wave-form
>that carries the image to the signal processer, which converts it
>to digital form for recording or output. There isn't a pixel to pixel
>correlation between the CCD's analog image acquisition and the
>digitally-recorded pixels of the encoding system. The extra CCD pixels
>can produce a more precise analog signal that is used to derive the
>digital conversion. However, if the CCD pixels are too numerous and
>small, a point of diminishing returns may be reached, especially in
>limited light.
>
> I believe the MegaPixel single-CCD cameras that use 690,000 (690K)
>active pixels for the video image, generally deliver a better image than
>those with only 360K active pixels or less. I wouldn't claim that this
>is true for those cameras that have 1.3K or 1.5K MegaPixel CCDs, as
>their pixels are so small, that they may have some disadvantages in low
>light, in the video mode.
>
> This applies more to single-CCD models, as most of those with 3
>CCDs give excellent video results with only 330K to 360K active pixels
>on each CCD.
>
> There is a lot of disagreement on this issue, as some people think
>the extra pixels are great for video images, while others hold the
>opposite opinion. I'm very happy with the video results I get with my
>1-MegaPixel camcorder (690K video-active pixels) and it does well in low
>light situations.
>
>Steve McDonald

I generally agree with the above, but add the note that the
1.5-megapixel cameras show little difference in low light
range compared with the 1-megapixel models, or even the
690k-pixel cameras (there is a noticeable difference here,
but it is relatively slight, being on the order of 1/2 stop or
so of difference in sensitivity - and with the finer "grain"
at the low light limit being shown by the 1.5-megapixel
models). The 1.5-megapixel motion-video images are
the sharpest of the one-CCD models, and can look quite
impressive on a good TV ***when shot under conditions
that do not emphasize the downside of megapixel CCDs***.
Unfortunately, these extra-sharp one-CCD models tend to
show considerable aliasing problems on not just gross
high-contrast edges in the image, but these can show also
in most textured areas in the image due to the higher
resolution and high image contrast of these cameras,
making for a VERY busy-looking image with motion. These
effects are minimized when there is little or no motion,
and with low contrast lighting or subjects (these cameras
can produce wonderful images on grey days, or inside with
good-but-soft lighting). I have come to appreciate the
strengths of my 1.5-megapixel TRV30 when it is used in
suitable lighting, and of my lower-resolution 690k-pixel
PC9 when it is used in contrasty lighting (and of my
3-CCD TRV900 and VX2000s when I don't want to deal with
the limitations of either of the one-CCD types...).
(For a comparison of these imaging types, see:
www.David-Ruether-Photography.com/camcorder--comparison.htm,
and for descriptions of video image faults, with
examples, see:
www.David-Ruether-Photography.com/vid_pict_characts.htm.)