Experiment with Top Stage Light from Two Directions

[DonSchaeffer]

I have two small flashlights. A white light flashlight points to the subject from the East and a violet/ultra-violet points to the subject from the South East. These are the only directions I could set up without shadows and without interference with my access to the microscope's controls. I can integrate the tip stag elights with the substage light and the condenser controls. (I am going to buy another white light for the South-East light but I don't have one yet).

These are pictures of an old mounted slide I made of some fibers from a flower.

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[LouiseScot]

They've come out quite well! Thinking out loud - it can be a challenge to get enough reflected light at high power. I suppose bright leds on goosenecks are a good idea but they can be quite expensive. Fibre optics are another option. You could also attempt relatively long camera exposures of static objects provided there are no vibrations!

Louise

[DonSchaeffer]

These are just flashlights. I intend to keep upgrading them. I mounted one light on a stand that was designed for a digital microscope. I mounted the other on a stand I fashioned out of mouth wash bottle. I have to look for a better alternative but so far that's what I have. Thanks for you comment.

[LouiseScot]

These are just flashlights. I intend to keep upgrading them. I mounted one light on a stand that was designed for a digital microscope. I mounted the other on a stand I fashioned out of mouth wash bottle. I have to look for a better alternative but so far that's what I have. Thanks for you comment.

Yes, I realise you're currently using the flashlights - I was just suggesting some possible alternatives
Louise

[MickH]

By sheer coincidence someone posted this on Facebook overnight although I guess there’s a chance the lights may be unsuitable for video: https://www.facebook.com/groups/Amateur ... 911883650/

[Placozoa]

I have some 3D glasses from a 3D movie, aka polarized lenses. If I put one in front of my top stage light oriented correctly it eliminates glare. Could this info be of use?

[MickH]

By sheer coincidence someone posted this on Facebook overnight although I guess there’s a chance the lights may be unsuitable for video: https://www.facebook.com/groups/Amateur ... 911883650/

I have found one I hope to buy for sale locally on FB marketplace so, fingers crossed, I’ll be trying it out later - alas, not for video as I’m not yet set up for that.

[DonSchaeffer]

These are just flashlights. I intend to keep upgrading them. I mounted one light on a stand that was designed for a digital microscope. I mounted the other on a stand I fashioned out of mouth wash bottle. I have to look for a better alternative but so far that's what I have. Thanks for you comment.

Yes, I realise you're currently using the flashlights - I was just suggesting some possible alternatives
Louise

Thanks Louise. What alternatives are you describing?

[LouiseScot]

These are just flashlights. I intend to keep upgrading them. I mounted one light on a stand that was designed for a digital microscope. I mounted the other on a stand I fashioned out of mouth wash bottle. I have to look for a better alternative but so far that's what I have. Thanks for you comment.

Yes, I realise you're currently using the flashlights - I was just suggesting some possible alternatives
Louise

Thanks Louise. What alternatives are you describing?

Just as above - "I suppose bright leds on goosenecks are a good idea but they can be quite expensive. Fibre optics are another option. You could also attempt relatively long camera exposures of static objects provided there are no vibrations!"
So very bright led lamps might be good but I don't know how bright your flashlights are. If you've got super bright ones maybe just make do with them

Louise

[DonSchaeffer]

I replaced my gooseneck lamp with flashlights. I have fiberoptic cable mounted inside the filter holder of the microscope. It's hard to mount them to shine light on the stage.

[Chas]

The individual strips in these 10w lights seem to make good low level illumination, each strip seems to run at around 24 volts and the negative and postive connections are labelled:

R7S J118 halogen fitting.jpg (42.12 KiB) Viewed 7310 times

The strips are held onto the big aluminium extrusion by some weakish heat-sink paste and so they can be got off with a penknife or something similar. I have stuck each strip onto to a peice of 1cm aluminium angle (I think its was some kind of kitchen surface trim) with double-sided scotch tape and have them controlled by a variable voltage power supply that looks a bit like this one:

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They run pretty cool/cold even at full power and the power supply will dim them without 'striping' the camera's display screen (the LEDS power off at about 18 volts)
I have been using them for opaque things and with the aluminium angle gripped to the stage by some clamps, so the light is quite low and shadowy:

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[Chas]

I suppose what I should have said is that the whole light units cost about £5 (in the UK) ..I suppose there isnt much demand for these LED units [they retrofit into the old linear-halogen bulb fittings].

[DonSchaeffer]

I like your led setup. Where did you get that power supply?

[Chas]

Don, I can't match the number on the front of the power supply exactly with anything I can find on the internet (bizzare, I know) But it looks exactly like the one in the photo I posted apart from the number on the front (and the fact that my control knob decreases in output when it is turned clockwise!)
Its specification is; 3-24 volt, 3 amps, 72 Watts, variable voltage .. there seem to be some on Amazon and some on ebay.
There is one quirk to it: The output connector has a larger internal hole/prong than the average phonecharger/ wall-wart, perhaps because it has a larger wattage, so for ease of general use it might be worth getting one that comes with interchangeable tips (I am using a tip with DC screw terminals to connect up ). 'SHNITPWR' seems to be a brand of them.

[DonSchaeffer]

Thanks Chas. Does it convert AC current to DC?

[Chas]

Yes, its output is DC, mine came with a 'screw terminal' connector amongst the various interchangable ends and this one has the + and - polarity marked on it (albeit in not very large font).

[DrPhoxinus]

This looks like a bigger version up to 12v but 5A
I am going to get this one because I have 6v and 12v scopes

https://www.ebay.com/itm/Adjustable-AC- ... 2498718764

Other models and plug types on ebay
Gerard

[DonSchaeffer]

I just bought one similar on Amazon. I have a USB switchbox all my powered lights are plugged into. Now thw swithchbox is connected to AC. I'm going to connect it to DC. I hope it works.

[Chas]

In "The microscope a simple handook" Conrad Beck mentions using two (red and blue coloured) oblique illuminators one above the other for picking out 'difficult structures' - I cant do that, but maybe you could do that with your setup?
A couple of pics :
The LED strip on the aluminium angle:

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I have got a couple of over-stages made of 6inch by 4inch 2mm thick acrylic (with some glass slides or bits of MDF stuck underneath for the moving-stage to grab onto) and the lights can be clipped onto the front /sides.
[Have to cut away a bit of the the acrylic where there is a sticking-up bit on the moving slide-gripper].

This over-stage also has a layer of self adhesive iron-loaded plastic stuck on top of the acrylic, with the idea that I can hold things down /add things, using magnets:

Beck magnetic material 640480.jpg (45.36 KiB) Viewed 7185 times

Maybe that is not so helpful to see, but I have cut a 3x1 bit out of magnetic layer for a glass slide to sit in
The iron loaded material is not massively 'magnetic' but maybe that is a good thing (and I now have some squares of it stuck onto the ends of a glass slide to hold down leaves/ feathers with little magnets.

(The pre-cut acrylic sheet and the self adhesive material for holding magnets both came from Amazon).

[Chas]

The reason to use acrylic sheet is that it is so much easier to work out where to cut away (if you need to )for the gripper and where to stick bits underneath.
(as you can see through it!)

[Chas]

Showing the 'terminal block' connector and bits of MDF underneath it all:

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The brown strip at the bottom is a rest for glass slides -- I am tempted to cut a hole in the middle of the acrylic and make a "Dark well" to go into the condenser mount.
WIP

[DonSchaeffer]

I think your set up is more elaborate and better crafted than mine. I am a cardboard, paper-clip, and tape man. I never developed the real ability to use adult tools.

[Chas]

Here is the hacksaw, cardboard, hot melt, sticky tape of a month ago :

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The the whole light unit was sawn in half lengthways.

[DonSchaeffer]

By the way, the AC to DC converter just happened to fit the supply plug to the connector I use for my powered lights. Hooray! I am buying a better adjustable stand for my second flashlight. Some fun, eh!
I still use substage light and a kind of adjustible stop filter too.

[DonSchaeffer]

I bought a new mount for the South East flashlight. This is a test using old self-made prepared slides of tree leaves and dandilion petals.

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[LouiseScot]

Very graphic images, Don! I could see them hanging in a gallery You know, I think imaging with reflected light has similar challenges to darkfield imaging - something I'm working on. I'm getting a 10W, 850 lumen LED bulb with a narrow beam angle to see if that will improve imaging.

Louise

[DonSchaeffer]

Thank Louise. I have a nice powered light but I just bought this:

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[LouiseScot]

Thank Louise. I have a nice powered light but I just bought this:2021-03-05_083509.jpg

We'll have to compare notes!
In the UK, I ordered one of these 10W LEDs https://www.ledbulbs.co.uk/products/aur ... dgu1024-40 though I'll have to reflect the light via a small mirror. I've also ordered a 10W Cree star LED which I can use to directly illuminate via the darkfield condenser. I'll see which works best. I've tried with a 3W star LED but it still wasn't quite good enough for photomicrography at 40x. Fine just for viewing but exposures were a bit slow via my Canon 1100d.

Louise

[DonSchaeffer]

I would have been happy with one of those if I had seen it. Although the connector may not fit. I have to use USB.

[LouiseScot]

I would have been happy with one of those if I had seen it. Although the connector may not fit. I have to use USB.

The one I ordered is a 'GU10' fitting which will go in my clip light. It runs from the AC mains - 230V over here. The LED bulb incorporates a driver circuit board which supplies the DC low voltage used by the semiconductor I have a separate power supply and driver to use with the Cree star 10W LED.

Louise