For hobby use I'd like to have a pair of glasses like you see surgeons
use, they have small compound lenses mounted on the regular lens. They are
expensive, how would I go about making a magnyifing lens that will focus at
about 18" and magnify 2 to 3 times?
I have searched for them on the net, but haven't found them, this is as
close as I got. Not to expensive either.
http://www.magnifyingaids.com/index.php?page=products&subcategory_id=5#16245
Mike

On Tue, 15 Jan 2008 21:00:37 -0600, "amdx" <amdx@knology.net> wrote:

For hobby use I'd like to have a pair of glasses like you see surgeons
use, they have small compound lenses mounted on the regular lens. They are
expensive, how would I go about making a magnyifing lens that will focus
at
about 18" and magnify 2 to 3 times?
I have searched for them on the net, but haven't found them, this is as
close as I got. Not to expensive either.
http://www.magnifyingaids.com/index.php?page=products&subcategory_id=5#16245
Mike



more like this?

http://www.sheervision.com/index.asp?PageAction=VIEWCATS&Category=3&gclid=CJCWx-Tk-ZACFRpdagodkXRB2Q

So what type lenses are used to make these?

http://www.sheervision.com/index.asp?PageAction=VIEWCATS&Category=3&gclid=CJCWx-Tk-ZACFRpdagodkXRB2Q

Yes, aren't those cool? and expensive!
So what type lenses are used to make these?

"amdx" <amdx@knology.net> writes:

http://www.sheervision.com/index.asp?PageAction=VIEWCATS&Category=3&gclid=CJCWx-Tk-ZACFRpdagodkXRB2Q

Yes, aren't those cool? and expensive!
So what type lenses are used to make these?

My dentist uses something like this, except that the two telescopes are
permanently mounted on the lenses of his regular glasses, instead of
having an external frame clamped to the glasses. Probably reduces
weight quite a bit.

The optics appear to be Galilean telescopes - a positive lens at the
front, a negative lens near the eye. The focal lengths used determine
magnification and size of the assembly. If you just want to experiment,
plain lenses from some place like Edmund might be good enough. But for
quality equivalent to the commercial ones, you'll probably need to make
each "lens" an achromat, and be anti-reflection coated. Or find a good-
quality pair of "opera glasses" and dismantle them for the optical
parts.

If you want to build the mechanical assembly yourself, you're going to
need access to a machine shop. The individual telescope barrels need to
hold the lenses in alignment, probably with some means of changing
spacing for focusing. Then the mounting frame has to hold the barrels
with exactly the correct spacing to match the user's eyes, with
exactly correct horizontal convergence and minimal vertical aim error
in order to get the two images to fuse properly into a stereo pair.
You'll need some amount of adjustability for this - either in the final
mechanics, or in a jig that you use to measure your particular eyes
(whose measurements are then used to make a non-adjustable framework
that is customized for you).

Essentially, you're building a specialized pair of binoculars that are
focused and converged at a specific distance instead of infinity.

Dave

I wonder what's the field of view for those.

If it's Galilean, it has to have a poor field of view.

Somewhere on the Sheervision web site it says that their lowest power
units (2.5X) have a field of view large enough to include an entire
mouth (they sell to dentists and dental hygenists) while the
higher-power ones show you only a portion of one.

more like this?

http://www.sheervision.com/index.asp?PageAction=VIEWCATS&Category=
3&gclid=CJCWx-Tk-ZACFRpdagodkXRB2Q

Yes, aren't those cool? and expensive!
So what type lenses are used to make these?

Thanks for those links. I don't understand why the language is
Italian

but the company is in Ohio.
Also I think it has a typo on the field of view it states
520mm.
Thanks again, Mike

"amdx" <amdx@knology.net> wrote in
news:cd285$478df487$18d6b40c$17241@KNOLOGY.NET:

more like this?

http://www.sheervision.com/index.asp?PageAction=VIEWCATS&Category=
3&gclid=CJCWx-Tk-ZACFRpdagodkXRB2Q

Yes, aren't those cool? and expensive!
So what type lenses are used to make these?

You can find these optical devices cheaper on eBay

http://snipurl.com/1xuah

http://snipurl.com/1xuaw

and a lot more, the trick is to put "surg* bino*" in the search
field, prices lower yhan 200 USD, can't say about optical quality.

Thanks for those links. I don't understand why the language is Italian but