"David Ruether" <rpn1@no-junk.cornell.edu> wrote in message

news:t9p7c.4370$vC.680@nwrdny03.gnilink.net...

> "Derek Hawkins" <someone@somewhere.com>

> wrote in message news:pMl7c.489$oF.10319@eagle.america.net...

> > I'm looking for a camera that when hooked up to a monitor could aid in the

> > drilling of printed circuit boards. It doesn't even have to be color.

> > Basically, the effective magnification would have to be about twice (or

> > more) than that in the following link;

> >

> > http://image.pbase.com/u41/eldata/large/27140910.CRW_8443_1.jpg

> A simple cheap single-element "close-up lens" fitted to the front of

> almost any video camera with a zoom lens should do what you want...

> --

> David Ruether

More:

Since most camcorders with built-in zoom lenses focus VERY

close at the "WA" end (useless - the camera is too close to the

subject), but not very close at all at the tele end (the distance is

useful, but the magnification is too low at correct minimum focus),

adding a diopter ("close-up lens") of the appropriate power to

the front will give both long space between camera and subject

and correct focus at the desired magnification (field-size) with

the zoom set longest-"tele". Some experimenting will be needed

to get the diopter power right, but sets of three threaded

"close-up" lenses of suitable mounting size are generally very

inexpensive. These can be quite sharp on video cameras, and

can be combined in pairs for higher magnification - and field-size

can be around 1/4" wide with this arrangement, and even

smaller with higher-power diopters or two-element achromats.

The cheap close-up lens itself can serve for front-element

protection, and a taped-on shield can easily be made to

protect the camera...

--

David Ruether

d_ruether@hotmail.com

http://www.David-Ruether-Photography.com