MicrobeHunter.com Microscopy Forum

The original Olympus base trans+epi illuminator for my SMZ is equipped with a 6V, 20W halogen lamp that provides poor intensity, although the bulb is new and the inner trans 45 degrees matt reflector has been replaced with a new front face mirror. I tried to acquire a flat LED under-stage lamp as suggested by forum member mrsonchus on another post, but it is not available locally. So I turned to a DIY illuminator, based on leftovers from previous tasks, mainly a reel of self-adhesive strip of 144 warm-white LEDs per meter.
Four 4.5cm-long sections (3cm sections might have sufficed) of the strip were cut and placed in a near-square array on top of a 6mm-thick aluminum plate, that served as heat sink. The sections were connected in series by soldering (see photo No 1). The power source is a small, variable voltage, 6-12VDC wall plug power supply. 9-10 Volts already yield very bright light.
The illuminator is placed on the floor of a simple riser, constructed of 25mm-thick square cross-section wooden bars and a tine sheet for floor. Uniform illumination of the stage plate is achieved by three simple matt-glass diffusers in series. They are vertically spaced at about 1cm distances, by using layers of 2mm-thick double-sided adhesive tape. The top diffuser is taped to the underside of the transparent glass stage plate.
This DIY is very inexpensive and IMO provides ample uniform light for my basic needs of viewing and plant dissection, although it is not sufficiently uniform for the camera.
All heat is dissipated through the heat sink, so the stage remains at RT, even after several hours that the illuminator is on.

Hope to attach some photos of dissected moss later. Only separated leaves for the time being.

Lovely job, does the job beautifully.

Is that moss I see on your table?

John B.

Thanks John B. Yes, two types of moss, soon to be shown in a separate post.

Hello,

I found an led array such as this was much easier to hook up...

https://www.ebay.com/itm/G4-5050-SMD-24 ... 3d63d3d3ab

BillT

Great job.. I was just attempting to show there were other ways to get the same results... I also prefer warm white to cool white.. To me it looks more like natural sunlight..

I'm a fan of homebrew gadgets. That strip LED illuminator looks handy and effective. Some commercial products can be used "right out of the box", but there's something to be said for building something out of materials already on hand.

Thanks folks. I had it on hands, yes, and the question was how uniformly bright it will be...

Hi Doron,

nice DIY project! You even have the "Lizenz zum Löten".

Diffusing light is not as easy as one might think. I once had to do with this in my job and ended up with using a very special acrylic glass that contained fine light scattering particles and diffused the light intensly without dimming it as much as ground glass or milk glass do. It was only made on order an we had to buy scrap parts as we needed to little amounts for a production run. Your diffusing attempt obviously worked well - the light looks very nice and soft.

With stereo microscope I see a big advantage in being able to use them where ever I go so a battery power option would be useful. For your LEDs it might suffice to use a stronger potentiometer to reduce the current for dimming the light.

Bob

MicroBob wrote:Hi Doron,

nice DIY project! You even have the "Lizenz zum Löten".

Diffusing light is not as easy as one might think. I once had to do with this in my job and ended up with using a very special acrylic glass that contained fine light scattering particles and diffused the light intensly without dimming it as much as ground glass or milk glass do. It was only made on order an we had to buy scrap parts as we needed to little amounts for a production run. Your diffusing attempt obviously worked well - the light looks very nice and soft.

With stereo microscope I see a big advantage in being able to use them where ever I go so a battery power option would be useful. For your LEDs it might suffice to use a stronger potentiometer to reduce the current for dimming the light.

Bob

Hi Bob,
Thanks for the compliment, sorry for my late response...
I just found out a better light diffuser than the ground glass surfaces: A thin white synthetic cloth! A year ago, I bought some cheap "cheese makers" filtration cloth, for my work on diatoms. There are different porosities, one of them was the 18 micrometer cloth. It was no great success, since it quickly clogged by the crude diatom "soup". BUT, it is a fantastic light diffuser. The smallest amount I to buy was 1 square meter, of which I still 0.95 sq m (so I can spare for colleagues who are interested). I replaced two of the matt glass diffusers with a single piece of this cloth for trans-illumination of my microscope.

Interesting approach. My Diascopic stand for my Nikon SMZ-U quit a few weeks back and I was unable to determine the cause. There is an opening in the base where the Halogen lamp resides directly beneath the glass cover. I removed the lamp and elevated the stand with using 1 inch feet. I then positioned a halogen ring light beneath where the halogen bulb use to reside. It works perfect and retains the darkfield capability as well. Initially I was not turning the intensity up sufficiently but have since addressed that.

einman wrote:Interesting approach. My Diascopic stand for my Nikon SMZ-U quit a few weeks back and I was unable to determine the cause. There is an opening in the base where the Halogen lamp resides directly beneath the glass cover. I removed the lamp and elevated the stand with using 1 inch feet. I then positioned a halogen ring light beneath where the halogen bulb use to reside. It works perfect and retains the darkfield capability as well. Initially I was not turning the intensity up sufficiently but have since addressed that.

What is a halogen ring light ? is the halogen bulb itself a ring-form tube ?
What wattage is the halogen light ? does it not heat the stage glass plate ?

Sorry. It is a simple ring light that utilizes fiber optics. The Actual Halogen bulb is located in the lamp house. Perhaps I confused you by saying Halogen ring light. So no there is no heat at the microscope stage. It is 150 watts.

Yes, fiber optics illuminations are great. I used one from Dollan-Jenner years ago. Can't afford them at home though.

They can be purchased on E-bay for relatively cheap.

Hi Hobbyst66,
great solution - I will keep this in my mind...as soon as the bulb is gone in my Olympus Stereo

Diluted milk is commonly used as a light diffuser, in some circles . It's full of tiny fat globules, which are great for de-speckling a laser.
Some of the function comes from the movements of the globules. I wonder how it would work if "fixed" in gelatin.

ChrisR wrote:Diluted milk is commonly used as a light diffuser, in some circles . It's full of tiny fat globules, which are great for de-speckling a laser.
Some of the function comes from the movements of the globules. I wonder how it would work if "fixed" in gelatin.

Yes, milk is an emulsion. The fat droplets are just the right size for effective light scattering. Milk is a great medium for demonstration of Brownian movement by microscopy. And to see how the scattering depends on the wavelength - blue vs red light, etc.
Gelatin and milk (and sugar) make a great Bavaria Cream so probably if the layer is thin enough, it can transmit light enough to see the scattering. Agar agar likely also creates such effects. So, the "challenge" is to prepare a thin layer of gelled milk on a slide.
For practical light diffuion, though, the 13 micron cloth layer is excellent. And stable over time, unlike the jelly.

Good for teaching kids why the sky is blue, too, with an aquarium and a phone torch
Is your cloth something like ebay item 173532274682 do you think? "tofu makers cloth".
Am always trying diffusers. Good quality tissue paper is surprisingly good. Thin expanded polystyrene too.
A separatrion layer works wonders.

Recently on another forum someone used milk to surround the subject, outside of a table tennis ball.

ChrisR wrote:Good for teaching kids why the sky is blue, too, with an aquarium and a phone torch
Is your cloth something like ebay item 173532274682 do you think? "tofu makers cloth".
Am always trying diffusers. Good quality tissue paper is surprisingly good. Thin expanded polystyrene too.

No, it was something like this
https://www.aliexpress.com/item/1000-me ... st=ae803_5
The problem was that a minimum purchase was 1 square meter. So I still have plenty of the stuff, because I had bought it for mud filtration but found out that it quickly becomes clogged, so I hardly use it. I can gladly send you a sample - please PM me if interested.