🚀 go-pugleaf

I have a couple of questions about the latest generation of CCD cameras
and I'm hoping someone can enlighten me.

The first question deals with auto-focus.  It used to be that cam-corders
that had auto-focus also had a lens that was visibly turning any time
the distance to the focal object changed.  Now, with the new and even
smaller cameras, you often don't see this.  Is the lens just smaller and
internal or is some non-mechanical means used to focus.  The manual to
my new Sony cam-corder says something to the effect that the camera
focuses by maximizing the difference in light intensity between adjacent
pixels.  I guess this makes sense - a blury picuture would have the
light more dispursed between pixels, and a sharp picture would have
higher contrast between pixels.  If a non-mechanical method is used to
focus, does anyone have any more details?

The second CCD camera question deals with the CCD's response to IR.
What is the response curve of a CCD camera?  How quickly does the CCD's
sensitivity taper off as the frequency of the light drops below visible
and into IR?   And how come I can see the IR on my monitor/view-finder?
(try pointing your TV remote at the cam-corder).  My potential application
is a pseudo-night-vision device.

Inquiring minds want to know!  Thanks!

-Bob
------------------------------------------------------------------------------
Bob Barker                                ...!uunet!umn-cs!tcnet!wd0gol!barker
Robert Barker & Associates                                barker@wd0gol.MN.ORG
(612) 949-0140