Glare problem with 144 LED right light for microscope

[lukego]

I am using an AmScope clone (Eakins) microscope with a 144 LED ring light and a 0.5x barlow lens and I have a major problem with glare. Green PCBs shine bright white, text etched on chip packages is invisible, etc. This happens even at low power levels when throttling down the dimmer. The problem seems to simply be that with my ~10 inch working distance the LED light is very hard and directional. (If I hold the ring light down around a chip, at a height of a couple of inches, then it looks gorgeous, but I can't solder that way.)

Can someone suggest how to fix this? I am tempted to buy an 8" beauty light from Amazon and bolt that on in the hope of getting soft omnidirectional light but I didn't find any reassuring posts in the archive about other people doing that and so I wanted to check now first.

Today I tried to make a softbox using cardboard, aluminium foil, and baking sheets but I'm not satisfied with the result. I also tried holding the ring light _adjacent to_ the lens instead of around it and this actually reduces the glare a lot but I'm not sure how consistent this would be with varying angles and working distances.

Help appreciated!

[sokoloff]

Can you use any diffusing plastic to soften the glare? Cut a ring out of some HDPE (milk bottle), or get an off-cut of frosted plastic somewhere (maybe from a light fixture lens or somewhere just as a test).

[chris_leyson]

Use polarized filters, one on the LED lighting and one in front of the microscope objective lens. I'm surprised nobody sells these as accessories. EDIT: linearly polaried sheet is not too expensive.

[wraper]

For PCB light source under angle work the best. LED rings around lens generally suck.

[KL27x]

You can buy light rings with individually dimmable quadrants. I found this is somewhat helpful. But the best thing is to tilt the microscope head 4-5 degrees. This removes the glare (and it gives a better view, IMO); no more adjusting the light. Obviously this is not that helpful if your microscope stand can't tilt.

[lukego]

Thanks for all the tips!

I'm leaning towards both a "beauty" ring light with diameter similar to max working distance, and a polarized lens.

My scope seems to already be at a 5 degree or so angle and I don't seem to be able to improve there (but yes straightening it makes glare worse.)

I am having trouble finding a suitable lens now. I'm googling for "c-mount" as the form factor and "CPL" as the filter type but I'm not exactly swimming in obvious choices. I'm also not sure if there are other parameters that I need to be conscious of.

Any more tips?

(This is all with the Eakins trinocular that's very similar to Amscope.)

[lukego]

So! I have made some progress. It's hard to discuss because the pictures from the camera are much different (worse) than the pictures from the eyepieces. I'll just go with that for now because I have already ordered the fancy autofocus camera from Eakins.

Here is the awful glare that I see when using the 144 LED ring light that came with the scope. This is with the 0.5x barlow lens at minimum zoom. (The camera also has a much narrower field of view than my eyes for some reason I don't understand?)



I can reduce the intensity of that ring light, which does reduce the overall brightness, but the glare is there even at minimum intensity.

My next step has been to mount a "beauty light" on the microscope instead. This is an 8" ring light powered by USB that cost $20 from Amazon. I've mounted it using a generic flexible camera tripod.



This is a massive improvement! The glare is basically gone, the colors are more vivid, and the writing etched on the chips is legible through the eye pieces. The brightness is a bit low, and maybe that will lead to eye strain over time, but a big step forward anyway. The camera doesn't quite do it justice but here is the image somewhat enhanced:



I'll try using this step and see whether the low brightness becomes a problem, and also how it all performs with the new camera once that arrives.

[lukego]

This is probably obvious to other people but I've only now realized that eliminating glare is not an end in itself and actually loses valuable information.

For example, the shine for glare is useful for knowing whether something is shiny, for example because it is wet.

I have a board that looks gorgeous under the soft sideways light but with hard overhead light is obviously scratched up, covered in gunk, wet from tacky flux residue, etc.

Just in early testing I'm happy having both the ring lights hanging overhead and adjusting them separately. Then I can always fiddle a knob to see what I am interested in e.g. what's written on the top of that chip, or have I cleaned up all the flux yet, or has the alcohol evaporated yet, etc.

I'm also really seeing in the screenshot above that the soft light isn't providing enough light for the exposure settings on the microscope camera, even though it looks good to my eye. I measure the light at about 1300 lux according to some Android app. I'll wait for the new camera to arrive before I bother looking into exposure settings or added more light etc.

[lukego]

I have a new camera which allows me to see and control exposure settings. I see now that my 144-LED ring light is only sufficient without the barlow lens. Once I have the barlow lens on then the gain/ISO kicks in hard and the picture looks awful. That's a pity because I really like the barlow lens for the working distance and for the lower magnification, especially via the camera which seems to have a much narrower field of vision than the eyepieces for some reason.

The next step will be to acquire a 6W dual gooseneck LED light and see if that provides the light that I need to use the barlow lens.

[sn4k3]

Solution: https://www.aliexpress.com/item/4000613976304.html
I have using this for sometime now, and is a relief, you have max light when needed and can regulate polarizer angle to elimate glare when need too. Belive me, you will not always use the polarizer at maximum effect/use, sometimes we need more or less and this piece let you regulate on fly. That said, permanent lens without easy ajust possibility will not be optimal.
Note there are cheap junk like: https://www.aliexpress.com/item/32523568334.html, dont buy it! Plastic crap with distorced image. Real solution is expensive but worth all cents.
Also i went this solution because gooseneck leds or other angle solutions will get on the way and stell work area, i like clean and easy solutions.

Example of jobs:
Lights on max, polarizer on minimum position:

Some test when i first got it:
 

[jfiresto]

... the camera which seems to have a much narrower field of vision than the eyepieces for some reason.

How big is the camera's image sensor? If the microscope has a c-mount photo port, it may project an image meant for a 1 inch image sensor. If it does and the sensor is smaller, you typically add an intermediate reduction/relay lens to shrink the image to match the sensor.

[lukego]

ou're
Solution: https://www.aliexpress.com/item/4000613976304.html
I have using this for sometime now, and is a relief, you have max light when needed and can regulate polarizer angle to elimate glare when need too.

That looks amazing!

What kind of microscope are you using? what's your working distance?

I'm using an Eakins trinocular (AmScope clone) and I'd love to be able to reproduce the picture you have. Just not sure if that will mount on my microscope and whether it will have the brightness for a 0.5x or 0.7x barlow lens e.g. 15-30cm working distance.

[lukego]

How big is the camera's image sensor? If the microscope has a c-mount photo port, it may project an image meant for a 1 inch image sensor. If it does and the sensor is smaller, you typically add an intermediate reduction/relay lens to shrink the image to match the sensor.

Interesting!

I have this camera:
https://www.aliexpress.com/item/32967911721.html

with this microscope:
https://www.aliexpress.com/item/4000013736134.html

... so that seems to be a Sony IMX290 sensor with size 1/2.8" connected to a microscope "23mm photo port." Does that sound like a mismatch that needs to be corrected by some adapter?

The microscope did come with some adapterey bits for the trinocular port but I never quite figured out how to use them... always suspected they were for connecting other kinds of cameras unlike the one I have, on which I did find a thread that fits without really understanding exactly what C-mount etc really mean... I'll have to do some homework.

[sn4k3]

That looks amazing!

What kind of microscope are you using? what's your working distance?

I'm using an Eakins trinocular (AmScope clone) and I'd love to be able to reproduce the picture you have. Just not sure if that will mount on my microscope and whether it will have the brightness for a 0.5x or 0.7x barlow lens e.g. 15-30cm working distance.

SM-4TP, basically same as yours
0.5x barrow len
4K cam with 0.35x adaptor on c-port

First video is from 4K camera, second is 1080p camera which im selling now with the adapter
Heres another video from 1080p and same setup with half polarizer:


The light ring will mount on yours, it have same dimentions as 144 led ring you use

PS: Your c-port adaptor is crap, but camera follows

[jfiresto]

...
I have this camera:
https://www.aliexpress.com/item/32967911721.html

with this microscope:
https://www.aliexpress.com/item/4000013736134.html

... so that seems to be a Sony IMX290 sensor with size 1/2.8" connected to a microscope "23mm photo port." Does that sound like a mismatch that needs to be corrected by some adapter?...

Right. If I were designing a microscope to make it as inexpensive to build as possible, I would split the intermediate image before it hits the eyepiece and direct half of the image out the photo port.

Here is something to try. Pull the other eyepiece, the one that isn't tied to the photo port, and hold it above (or in?) the port – and see if you can get the same view that fills the other eyepiece.

[lukego]

How big is the camera's image sensor? If the microscope has a c-mount photo port, it may project an image meant for a 1 inch image sensor. If it does and the sensor is smaller, you typically add an intermediate reduction/relay lens to shrink the image to match the sensor.

This looks like the ticket:
https://www.aliexpress.com/item/32855848880.html

I'll order the 1/2 and 1/3 and see which one helps me out the most. Or if I'm on the wrong track please do shout at me :-)

[lukego]

The light ring will mount on yours, it have same dimentions as 144 led ring you use

I'm sorely tempted :-). The specs on the Aliexpress store are a bit sparse though. Do you know how many watts/lumens the LEDs are rated for? I'm not satisfied with the brightness of my 144 LED ring light because when I use the 1/2 barlow lens then the cameras I have need to use gain for their exposure and that impacts image quality. I'd like to avoid that problem if I'd spring $250 for a super-duper ring light.

There aren't many sales/reviews on that Aliexpress store either - is that the same unit from the same seller that you have?

I reckon I'll wait for my gooseneck lights to arrive and see how I get on with those first but the polarized ring light does sound like a major potential upgrade.

PS: Your c-port adaptor is crap, but camera follows

What do you mean about the c-port? Mostly that it needs a reducing barlow lens for the field of vision, or something else? and about the camera? I'm all ears

[jfiresto]

... I'm not satisfied with the brightness of my 144 LED ring light because when I use the 1/2 barlow lens then the cameras I have need to use gain for their exposure and that impacts image quality....

You lose an f-stop from the microscope's 50:50 beam splitter (my interpretation of "simul-focal") and a couple more f-stops from the 0.5X barlow lens. I faced the same issues and bought a used mirrorless camera body with a much larger sensor. Substituting a micro four thirds camera will likely win back more than three f-stops. If the microscope follows a not uncommon pattern, the camera may also need no reduction lens, which is good as a lot of the cheap ones noticeably degrade the image.

[lukego]

Hey what camera(s) and camera attributes would you guys recommend for the trinocular port? Sounds like a larger sensor would help, but maybe something else too, and what's s good camera that would check all the boxes?

Maybe at some point I will make the autofocus camera into a separate inspection scope and put a different fixed-focus camera on the trinocular.

[lukego]

I have checked the inventory on the microscope kit that I bought and the "spare part I never worked out what to do with" is in fact a 1/2 reducer. So I'll fish that out and test it when I get home. I'm not sure why I couldn't make it fit in the beginning, perhaps it is either/or with another lens piece that I had already installed.

I need to do some reading about optics. I'm not sure whether to expect the light strength to increase, decrease, or stay the same with the 1/2 reducer lens. On the one hand it seems like more lenses means more loss but on the other hand I'm using a 1/1.8" sensor with a 28mm lens and that seems like it would be discarding most of the light rather than capturing it. So I'm quietly optimistic but certainly in for an education :-)

[sn4k3]

I'm sorely tempted :-). The specs on the Aliexpress store are a bit sparse though. Do you know how many watts/lumens the LEDs are rated for? I'm not satisfied with the brightness of my 144 LED ring light because when I use the 1/2 barlow lens then the cameras I have need to use gain for their exposure and that impacts image quality. I'd like to avoid that problem if I'd spring $250 for a super-duper ring light.

i don't know lumens or watts they have, i surely can test for that but...
This led ring appear to me have less brightness than the 144led, because it got 120led only plus polarizer glass that dim a little bit, but who cares, the real important factor is suficient light and image quality, which i got both. I got same magnification and working distance as you. And you have the videos to see for yourself. Now the more you zoom less light will enter and image on camera will be very dark. Eye ocular will always have better light and better view then the camera, but again you have my videos to check out.
What i do:

• Set manual exposure on camera from 14ms to 16ms (NEVER USE AUTO-EXPOSURE!!!)
• Put the minimum zoom on scope
• Ajust brightness on camera for a maximum accepted and confortable level without ruin imagem
• Now check at max zoom if brightness is enough

Following that you will cover all your range and your recordings will be good.

There aren't many sales/reviews on that Aliexpress store either - is that the same unit from the same seller that you have?

It is, they are always refreshing the article and reviews go away. There aren't many sells of that stuff because is "expensive" and people rather like buy cheap, but we pay for what we get most of the times.
There are other sellers with same stuff, but i recommend that seller.

I reckon I'll wait for my gooseneck lights to arrive and see how I get on with those first but the polarized ring light does sound like a major potential upgrade.

Trust me, i tried everything too to solve the glare. 144 led -> goosenecks -> plastic polarizers -> led clips -> other craps. All a waste of money and time.
Goosenecks well placed will solve your problem or angle quadrant leds BUT the goosenecks will always be on front and not rotate when you move your scope head. I hate things on the middle and slowing you down. You will have to ajust position tons of time if you move your scope head a lot like me.
The led ring i use now was the best thing i ever buy for the scope, what a relif, it fix the glare and give you the freedom of ajust the polarizer just turning the wheel.
PS: If this led ring dont have the desired brightness for you, you can merge it with your goosenecks to increase the power, or mod it with super bright leds.

What do you mean about the c-port? Mostly that it needs a reducing barlow lens for the field of vision, or something else? and about the camera? I'm all ears

Yes it needs an adaptor, but that adaptor is not good and long.
Camera is low quality and cheapest they can put in to have a "good deal/price". Buy bundles is always a tradeoff because you will never get all quality. Scope is ok then they trown a buch of crap equipment like that adaptors and cameras of low quality to atract the buyer.
The best move is buy everything separate and finger picked.
That being said, your camera and adaptor is what kill your image and make don't have the required light. Look my first video, it looks dim? With less power than your 144 led ring plus a polarizer and still look shiny... No post process. But if required premier can do miracles and fix your image with filters.

Check this post: https://www.eevblog.com/forum/buysellwanted/fs-(eu)-microscope-1080p-60fps-hdmiusb-camera-0-35x-len-adaptor/msg2804054/#msg2804054
There you can find links to my camera and proper adaptor.
Reject all plastic lens and embrace real glass ones

PS: My 0.5x barrow len is original made from glass, if i would you, check and see if yours it made of glass or plastic...

EDIT: I also trust this store: https://www.aliexpress.com/item/4000689771351.html

[jfiresto]

... I need to do some reading about optics. I'm not sure whether to expect the light strength to increase, decrease, or stay the same with the 1/2 reducer lens. On the one hand it seems like more lenses means more loss but on the other hand I'm using a 1/1.8" sensor with a 28mm lens and that seems like it would be discarding most of the light rather than capturing it. So I'm quietly optimistic but certainly in for an education :-)

I am pretty tired and probably should not have been commenting.

A glass 0.5X auxiliary lens should win you a couple f-stops because it is gathering light from four times the area.

The missing 0.5X reduction lens between the microscope and 1/2.8 inch image sensor should cancel that, if using the lens matches the sensor to the full field of view.

Projecting the full field of view on to a 4/3 inch sensor could win over five f-stops: a bit less than 2 stops for the full field of view plus 3.7 stops for the the 13X larger sensor area (2**3.7 = 13). But I probably should sleep on that!

[lukego]

I have done a little experimentation.

First, I seem to have 2/3 field of view via the camera, 2cm wide verses 3cm wide in the eyepiece without a Barlow lens.

Here is what comes out of the camera with the 0.7x barlow lens, ring light at full brightness, longest shutter time:


I would like to play with the exposure settings but I wasn't setup for recording and operating at the same time.

There is obviously more than enough light there, the only problem being glare, which makes the polarized ring light seem like a good idea.

(My desk is wobbling too. I have to work on that.)

Here is the microscope itself including the spare bits I couldn't find a use for:


... but those bits don't have any glass in them so I don't think they are useful here. Maybe I the microscope head has a built-in 1/2 reducer and I could perhaps swap that for a 1/3 reducer for a wider field of view but I'm not confident about that.

Any thoughts? Otherwise I guess the next step will be to try with my goose lights when those arrive and/or play with the exposure settings while recording.

EDIT: I also have this video without the barlow lens but the framerate come out bad because of the way I recorded it (screen capture while viewing):

[lukego]

I reckon I'm coming full circle here, to the problem being glare rather than brightness, and it sounds like you guys have proposed a couple of good solutions: polarizing light from AliExpress to fix the glare problem and a stronger reduction lens for the field of view (AliExpresd has a 1/3 lens I can substitute for the current 1/2 from the microscope supplier, Eakins.)

Thanks for all the input! I will report back with what I come up with. O won't be shocked if the 1/3 lens has some issues, e.g. artifacts around the edges, but we will see.

[dreamcat4]

So where are we at now with the 8 inch beauty light? It's still worth it? Or it's not worth it for the $20 to save towards the $250 polarized ring light ?