Looking for LED Ring Illuminator

Here you can discuss different microscopic techniques and illumination methods, such as Brightfield, Darkfield, Phase Contrast, DIC, Oblique illumination, etc.
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Mr Galasphere
Posts: 40
Joined: Wed Dec 23, 2020 12:08 am

Looking for LED Ring Illuminator

#1 Post by Mr Galasphere » Fri Jan 13, 2023 10:51 pm

Hi,

I'm looking for a LED ring illuminator for my Amscope SM-1TS stereo microscope.
Amscope has bewildering number to choose from, up to 144 LEDs. Do I need 144? Is less OK?
The are many identical looking rings available that cost less than the Amscope offerings. I assume they are all from the same factories.
Some reviews have complained about the light being too blue on some models. Has anyone here encountered this?
Lastly, recommendations would be appreciated.

Thanks,

Roger

MichaelG.
Posts: 3976
Joined: Mon Apr 10, 2017 8:24 am
Location: North Wales

Re: Looking for LED Ring Illuminator

#2 Post by MichaelG. » Fri Jan 13, 2023 11:51 pm

144 LEDs should give you both more light, and more uniform light

Whether that’s important to you, I can’t say.

MichaelG.
Too many 'projects'

Scarodactyl
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Joined: Sat Mar 03, 2018 9:09 pm

Re: Looking for LED Ring Illuminator

#3 Post by Scarodactyl » Sat Jan 14, 2023 1:25 am

Some are blueish but they're mostly fine, even the cheap ones are OK. It is fun to use cheap polarosing film to cut out a large ring and polarize the light thag comes off them and then attach a rotating camera polarizer to the scope so you can tune specular reflections.

Mr Galasphere
Posts: 40
Joined: Wed Dec 23, 2020 12:08 am

Re: Looking for LED Ring Illuminator

#4 Post by Mr Galasphere » Sun Jan 15, 2023 6:01 pm

Thanks for the input.
I decided to give this one a try: https://www.amazon.com/dp/B075MCNZFL?re ... tails&th=1
Scarodactyl wrote:
Sat Jan 14, 2023 1:25 am
Some are blueish but they're mostly fine, even the cheap ones are OK. It is fun to use cheap polarosing film to cut out a large ring and polarize the light thag comes off them and then attach a rotating camera polarizer to the scope so you can tune specular reflections.
That looks interesting. I'll have to give it a try

apochronaut
Posts: 6272
Joined: Fri May 15, 2015 12:15 am

Re: Looking for LED Ring Illuminator

#5 Post by apochronaut » Sun Jan 15, 2023 7:42 pm

Make sure the i.d. is large enough for your objective. That is a common mistake.
For somewhat more you can get one that will turn on any combination of quadrants, so you can get various oblique illumination arrangements. I paid about 80.00 for the one I bought and it is bright enough for l.w.d. situations too.

The nimber of leds is somewhat misleading because leds can have varying outputs. It is the total wattage that is important. 2 or 3 watts can be pretty dim at distance with some subjects.

Mr Galasphere
Posts: 40
Joined: Wed Dec 23, 2020 12:08 am

Re: Looking for LED Ring Illuminator

#6 Post by Mr Galasphere » Wed Jan 18, 2023 10:25 pm

The Bikani LED light ring works just fine. Doesn't appear bluish to my eyes.
It does hang down about 2 cm from the objectives.

jfiresto
Posts: 342
Joined: Fri Feb 15, 2019 8:19 am
Location: Northern Germany

Re: Looking for LED Ring Illuminator

#7 Post by jfiresto » Thu Jan 19, 2023 1:07 pm

If you play some more with the LED ring light at high magnifications, you may discover it is more blue than you thought and introducing chromatic aberration. Another issue, not explicitly raised in that thread, is that you may find its strong blue peak is reducing both the resolution and contrast at high magnifications. Below are a couple photomicrographs of a finely lithographed, 2732 EPROM taken with a Wild M7A and center-cropped to show the individual E-PL8 camera pixels. The first shows the EPROM cells under an incandescent ring light

2732_incandescent_tinted.jpg
2732_incandescent_tinted.jpg (132.82 KiB) Viewed 1448 times

and the second under an Amscope 144-LED, 6500K(?) LED ring light

2732_6500K_LED.jpg
2732_6500K_LED.jpg (124.76 KiB) Viewed 1448 times

I have lightly boosted (tinted) the incandescent image toward blue to bring it closer to the LEDs'. Despite doing that, the incandescent image has considerably better contrast and sharpness, I believe from the microscope misfocusing the LEDs' strong, blue peak.
-John

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