Experiment with Top Stage Light from Two Directions

[DonSchaeffer]

At least what I ordered was supposed to be for microscopes (albeit Stereo ones).

[Chas]

The 'Angel eyes' headlight rings mentioned by dtsh in the 'microscope adaptations' section ['AO cycloptic illuminator'] seem interesting:
The set I got were 'Qasim 1-Pair White 70MM 60SMD COB LED Halo Ring Angel Eyes Led Car Headlight with lampshade Cover 12V 24V DC' from Amazon [£10.50 for a pair]:
They come in (cold)white, red, green, and orange (I think).

Resting on the condenser mount, under the stage:

x10 underneath.jpg (86.43 KiB) Viewed 2724 times

Resting on top of a slide:

Angel eye resting on slide grass midge.jpg (33.19 KiB) Viewed 2724 times

The (white) one I got runs at a glow at 8.5 volts and is at its full power at about 11.5v and has some kind of current controller in its wire that means it isnt damaged by higher input voltages (tried it at 24v and it seems to run fine).
To get a dark background the condenser needed to be dropped out of its mount.
Lots of colours potentialy

[Chas]

Here it is under the stage:

Resting on the condenser mount under the stage.jpg (56.27 KiB) Viewed 2724 times

The black bit sticking up out of the condenser mount was a (failed) attempt to make a dark-well.

[DonSchaeffer]

I love your inventiveness. I glued a piece of light condi\ucting cable to a flashlight and inserted the cable right into the filter holder. There is an automatic hot spot (not very strong) coming from the back of the visual field.

[Chas]

I havent tried one, but there are tiny (1/10, 1/20 inch) SMD LEDS being sold with wires attached to them ..lights for model-makers.

Because of the little hotspot I had in the midge photo, above, I tried resting the glass slide directly on top of the Angel Eye, so that the light came up from underneath and into the end parts of the glass slide.
I was quite surprised; the midge was as nicely lit as when the the light was shining down into and across the slide, here is a crop of the head:

N x10 head cropped slide resting on angel eye.jpg (34.44 KiB) Viewed 2705 times

(This pic is was taken with a modern Nikon x10 objective, unlike the previous pics that were taken with an oldish cooke x10 ).

[Chas]

Maybe one day, childrens microscopes will come with LEDS embeded into the stage !

[DonSchaeffer]

That would be a good idea. Why not adult microscopes?

[Chas]

Maybe it has a use for looking at the upper surface of opaque objects(?) but I dont suppose that many of these are put in mountant.

[Chas]

Ha, just to say that I misunderstood what was going on:
If the internal surface of the ring light is blacked out, the exposure time more than doubles ..so the light isnt just going straight up and into the ends of the glass slide and then travelling along to the midge, quite a bit is of it is going in obliquely.
The hot spot seems to be something to do with the microscope objective /microscope body/ tube-length combination - I had a hotspot with the Nikonx10 on a different microscope body and then got rid of it by pulling out the draw tube.
So I dont think that mounting LEDS upwards on a stage would work .. I think they would have to be in a bit of a well.

[DonSchaeffer]

That is really a good idea. In my case the condenser would get in the way I think.