working on this small of a scale (3 mm diameter faces--
imagine) makes an Optivisor-- Obsolete. Maybe there is
something I don't know about here, but as far as I know they
only make them up to about 5 power and any thing higher would
make using them very difficult.
The keeler optics, per an email from skip, are probably out of
the price range. At least they are for me. And though they are
likely far clearer optics, I’d expect that they magnification
(4x?) might still be too low for you.
You might wish to try what I’ve done for the last 25 years. I
use a single monocular eye loupe, and work with only one eye at a
time. this takes a bit of practice, but once you learn to keep
both eyes open and don’t squint or strain, just concentrate on
what your seeing through the loupe, then it works for me for
extended periods of time, despite my eyes having fallen victim
to various laser surgeries needed to control diabetic damage.
The key to eye loupes is the quality of their lens. Most
“watchmakers” loupes are low power single lens optics. In a
word, lousy. What you want is the quality of lens that you see
in a diamond grading loupe, a hastings triplet. A ten power
hastings triplet loupe is clear and undistorted. The working
distance is only 1 inch from the front of the lens, but you’d be
surprised at how much you can do with that once you get used to
it. I can do whole pave’ set pieces entirely within that working
distance, and carving small details on a wax is not any more
difficult. At 10x, even tiny details are easy to see, and
watching what the tool is actually doing close up makes it much
more controllable.
Obviously, the standard hand loupe isn’t the way to do this.
Get one of the baush and lomb eye loupes with the 10 x hastings
triplet. GIA sells them if you can’t find them in your local
favorite supplier’s stock. They are not cheap. last one i
bought, several years ago, ran about 45 dollars, and I expect
they are more now. They come without any headspring attached,
which is silly since they are too heavy a lens to easily hold in
an eye socket for more than a couple seconds. There is a
headspring attachment made, into which the loupe clips, but I
find it akward, too long, and funny feeling. I take a clock
spring, or the headspring pirated from one of the cheap single
lens headspring loupes, and fit it to the 10 x one. Usually
means drilling a little hole in the spring, and another two small
ones in the loupe. The end of the spring gets bent over into the
farther hole, while a rivet joins the both at the hole closer to
the edge of the loupe. Not hard to do. Then, I also take a
burr, and cut a hole, about a half inch diameter, but oval, into
the side of the loupe that will face my nose when it’s over my
eye. This way, I can move my focus from through the lens, to
through the hole, where vision with both eyes is then possible
to see what’s other than in that 1 inch from the loupe space.
Makes useing the loupe much more convienient, while still not
keeping enough light out from in back of the loupe to keep it
glare free in use. Functions then a bit like bifocals to, except
it’s glancing to the side to see normally, and back straight in
front to use the loupe. And when you don’t need the loupe for a
bit, the spring holds it to your forhead instead of to you eye,
so it’s right there when you need it again. With a little
practice, I’ve found this arrangement to be convenient and
effective, and well within my budget as well.
Hope this helps.
Peter Rowe