[Tfug] Yet another optics question

[Jim Secan]

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"
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.

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

And Merry Christmas/whatever to the list from Microsoftville.

Jim

Bexley Hall wrote:
> The bulb in the light source for my stereomicroscope is made
> of unobtanium-247 (not quite as hard to come by as u-248 but
> damn close!).  And, it throws off a *lot* of heat -- 20W!
>
> I am tempted to replace the light source with a set of
> white LEDs.  This frees me from the worry of having to
> worry about finding another lamp N years hence as well
> as cutting down on power consumption, etc.
>
> But, the light source has some optics in it to produce a
> focused light:
>
> http://www.science-info.net/docs/b-l/BL_Nicholas_Illuminator.pdf
>
> The "lens" (lens assembly?) appears to be a pair of plano-convex
> lenses with a "light pipe" between them (I think this is just to
> compensate for the mechanical design of its mount -- but it
> may have optical consequences too?).  I.e. the entire lens
> assembly is probably 2 inches thick.
>
> My question:  do I need to situate the LEDs at the same position
> of the filament in the original bulb?  If so, that would suggest
> I need to use a single ultrabright LED as trying to locate multiple
> LEDs in the same small region would be problematic.
>
> Or, should I just buy a few bulbs (they are about $10 each), hope
> they don't fail prematurely, and just live with all the heat
> thrown off, etc.?
>
>
>
>
> _______________________________________________
> Tucson Free Unix Group - tfug at tfug.org
> Subscription Options:
> http://www.tfug.org/mailman/listinfo/tfug_tfug.org
>