[time-nuts] Subject: Re: I love the smell of tantalum in the morning
Charles Steinmetz
csteinmetz at yandex.com
Tue Nov 8 03:54:47 UTC 2016
Jeremy wrote:
> Amazon indicates the different lenses simply snap in and out. Any idea how
> easy/practical this is? It it better to have two completely different
> visors each holding different magnification lenses?
Quite easy -- the lens plates are held onto the front of the visor by
two plastic pins that just snap in and out. You can see the heads from
the outside (as opposed to the eye-side) at the far left and right of
the lens plate.
That said, IMO it is always more convenient to have each lens plate
mounted in its own visor.
I have to say that contrary to the original post, I find the 3.5x lenses
WAY too strong for SMD work. The working distance is only 3-4" -- not
nearly enough to work safely with hot tools, or comfortably. Even the
2.5x lenses, with 6-8" of working distance, are too strong for me. For
anything that requires working on the object you're looking at (as
opposed to just examining it), I recommend staying at 2x and below (2x,
1.75x, 1.5x).
Finally, Donegan makes two series of lenses -- rectangular plastic
frames with optical glass lenses, and rectangular plastic frames with
molded-in plastic lenses. The glass lenses are more expensive, but the
large difference in optical quality makes them the only real choice, IMO.
At substantially greater cost, you can get "surgical loupes" (a/k/a
"dental loupes"). These have compound optical systems, so you can get
longer working distances at a particular magnification than you can with
a single lens (like the OptiVisor has).
Best regards,
Charles
More information about the Time-nuts_lists.febo.com
mailing list