On May 12, 2006, at 5:12 PM, Alan Beane wrote:

> So out of curiosity do the HD cameras capture higher than 640x480?

very carefully!

<rim shot>

But seriously - they just have a CCD with more pixels in it. That, by
itself isn't a big trick - its unloading the image 30 times a second,
moving the data around, writing it to tape or whatever - that's the
part that makes an HD movie camera non-trivial. Even HD resolution is
not very big in comparison to the resolution of still images and
monitors. If you had a full non-interlaced HD frame, its still
extremely low quality in comparison to what still cameras do now.
Mostly, it has to do with the way we see moving images. If you put up
a 640x480 still image that's a foot or two across, it looks like
crap, but if you make it move, then your mind just interpolates all
the junk away and it looks terrific. In a moving image, our brains
put the data in that ought to be there, so we just don't need huge
resolutions to get video that looks good. However, we are pretty
sensitive to motion, and if the frames don't update about 25-30 times
per second, then we notice it.

SR