[Tfug] Yet another optics question

[Bexley Hall]

Howdy Jim,

Cold enough (yet) for you?  :>

> Looking at the manual you reference, the first thing to note is that the
> figure appears to be miss-labeled.  I believe that #12 is the lens mount
> assembly, #13 is Lens B, and #14 is the retainer for Lens B.  That 
> said, I don't see evidence in this picture that there's anything
> but air between the two lenses indicated in the drawing.  What do you
> mean by "light pipe"

I misspoke.  <:-(  I had assumed that this was actually one
solid piece of glass/plastic and tried to describe it AS IF
it was two plano convex lenses glued to a cylinder of glass.
Instead, it is, as you say, two discrete lenses.  I haven't
removed them from the assembly (for fear of cracking the
metal "spring clip" that holds each in place) so I can't
say what the "inside" (i.e., the sides facing each other)
are shaped like.  The "outsides" have a very high degree
of curvature, though.

> between the two - is there something you can see in your
> hardware that's not shown on the manual's figure?
> 
> How difficult would it be to experiment with the setup?  Pull
> off the full lens assembly and try focusing one or more LEDs 
> and see what you get.

I've tried that.  I get "light" out the other side.  :>
It, however, is hard to determine what effect moving the
LED around has on the quality of that light (intensity,
focus, etc.).  Keep in mind that I have to look through
the objectives to see what the hell is going on (which
means I'm "working blind" as far as the LED's position
is concerned)

> Another, non-optics, issue would be the spectrum of the
> light.  The lamp is going to give off a different spectrum 
> than the LEDs (unless you carefully match them), which may 
> make things look different under your 'scope.

Yes, but I can't see how that would materially matter.
It's like a big, binocular magnifying glass (not like
a traditional microscope).  So, the blue-white color of
the LEDs differs from the yellow-ish color of an incandescent
lamp.... which also differs from the color of the ambient light
in the room!  :-/

> I think you're safest in biting the proverbial bullet and buying
> light bulbs for the future.

Yeah, that is what I feared.  But it feels like I am just kicking
the can down the road for the inevitable day when I *can't* buy
a replacement bulb...

> And Merry Christmas/whatever to the list from Microsoftville.

And Virtual Santa?!