Can a light source damage lens?

[Plasmid]

This weird cloudy spot develop on the lens overnight and I can't get rid of it anyone experienced this before?
This particular lens sit just below the eyepiece tubes and diopter., Needless to say the microscope is always over when not in use and the temperature inside the home has not fluctuated nor the humidity, the only changes were two LEd gooseneck lamps that were added to each side of the base. The problem was not present two days ago nor was it 3 weeks ago when I purchased the microscope, the head has not been taken apart until now.
Thank you for taking a look at this issue


23.9x2.0mm

[Plasmid]

Here's a better view of the lens. Whatever it is it's internal, nothing I do seems make a difference at all, even try polishing one of them knowing that there is no fix in it and it had no effect. I wonder what the purpose of the lens are.?

The bottom one is the worst of the two, but as you can see on the first picture it's starting to present also on the other one as well. The side that's affected it's the one distal side, from the viewers point of view.

[apochronaut]

You refer to this as a lens. Does it have a non-plane surface or is there evidence of a cement layer?

[Plasmid]

You refer to this as a lens. Does it have a non-plane surface or is there evidence of a cement layer?

I'm honestly not quite sure what they are they might be some correction lenses, they are held in place by a spring clip. As I mentioned before after removing them I've noticed that I have to focus down a bit more when compared to when they were in place.

[Greg Howald]

Even a piece of plain glass in the light path can affect focal length, so by removing them If focal length changes that might be an expected result. The question is, are they corrective lenses. If so you might not be able to focus well at higher magnifications like 100x. I'll take another look a your post to see if I might actually be helpful to you.

[Greg Howald]

I don't know the type of scope or how old it is but I do wonder if the lens actually has coating on it that is damaged. As a last and very last resort, if that is a damaged coating on the lens you can remove the coating with 90 percent alcohol. If the problem is internal the alcohol will have no effect. If the alcohol removes the coating the lens will be clear and beautiful almost immediately. If that happens be careful because the amount of light reaching your eyes may be dramatic. And no. No external lighting source should affect the quality of the lens or cause it to change.
Greg

[Plasmid]

So the scope is a stereo, fairly new, a copy of the olympus sx67 i believe. The highest mag on it is 75X with no barlow lens, the two lens in question really dont appear to make a difference in image quality, I tested the coating theory and the alcohol did not remove it however a very sharp razor at an angle was able to remove some of it,that along with a microfiber polish and the whole top cote was removed, with that being said the fogginess appears to be in internal and he had no effect on it. Looking at my other stereo microscope with the same design similar lens cannot be found so I wonder what the purpose of it was.
Now that I think about it there is a slight change in image quality, a lot more light comes through and so the image is a lot brighter. Literally have not been able to find anything on regards to their purpose.

[PeteM]

My recollection is that the Olympus SZ scopes put a flat coated glass window in that position - I've assumed to keep dust and humidity out of the head where they can lead to fungus etc.

Pretty baffling that this appeared appeared just sitting for a week or so. Were the eyepieces out?

My first impression of the worse of the two is that it might be fungus - but alcohol should remove that if it hadn't had time to etch the glass.

Only reason to suspect an internal problem would be if the glass were cemented - but that doesn't (?) appear to be the case. If you wet both surfaces of the glass does the haze go away?

Pure alcohol can sometimes just move around something like an oily film, so I suggest trying something like ROR lens cleaner as well. Or just soap and water given they've been scraped and polished down to glass. Might add that polishing can leave a haze - could it be you've swapped one haze for another??

In any case, it seems you can use the scope without the windows - and that it was an affordable used buy? FWIW, with respect to the original question, things like high power lasers can damage the glass in objectives over time -- but I can't imagine ordinary LED lamps doing that.

[MicroBob]

Hi, some thoughts:

- is it a lens? Look through it, does it affect the view?
- Could it be a sandwiched filter?
- If it is not a lens but just a protective glass - can you just replace it?
- Is it possible that the decay was already there, and you just see it now with the stronger lamp?

UV light can damage cement layers in slides and lenses. But the normal glass types shouldn't decay over night.

Bob

[Greg Howald]

Here's a thought. Placing a single polarizing sheet in place of the damaged lens will change the focal length ( maybe for the better) and will reduce the amount of light presented to the eye.

[Plasmid]

[quote=PeteM post_id=100941 time=1616649442 user_id=698

Pretty baffling that this appeared appeared just sitting for a week or so. Were the eyepieces out?
The Eyepieces are only removed for recording a video, every once in a while. The issue started to get more noticeable after the new lamps were installed, im guessing it became more noticeable with the 3200k vs the 5000k before.

My first impression of the worse of the two is that it might be fungus - but alcohol should remove that if it hadn't had time to etch the glass.
Not sure about the fungus, definitely internal, not even the razor or trying to edge a cut on the surface has an effect on the haze.The top coat was successfully removed.

If you wet both surfaces of the glass does the haze go away?
Yes for a second but as soon as it dries becomes visible.

- could it be you've swapped one haze for another??
Yep at this time its more of a dissection than a salvage, want to figure out the cause.

In any case, it seems you can use the scope without the windows - and that it was an affordable used buy?
Definitely a bargain, the scope had never been used, brand new in the boox for $100usd

FWIW, with respect to the original question, things like high power lasers can damage the glass in objectives over time -- but I can't imagine ordinary LED lamps doing that.
I considered the heat of the lamps playing a role since they run a bit hotter after long use, but the lens are too far up and away from the heat source.
[/quote]

Thank you.

[Plasmid]

Hi, some thoughts:

- is it a lens? Look through it, does it affect the view?
- Could it be a sandwiched filter?
- If it is not a lens but just a protective glass - can you just replace it?
- Is it possible that the decay was already there, and you just see it now with the stronger lamp?

UV light can damage cement layers in slides and lenses. But the normal glass types shouldn't decay over night.

Bob

I believe now they are more of a protective glass, i contacted accuscope since they import the same model from China, but they dont sell those parts, same with microscopeinternational.com out of NY, just got an email saying I'll have to ship it to them.
The new lamps did make it more visible i guess, however two days ago the image was clear, then suddenly the right side was completely distorted.

[Plasmid]

Here's a thought. Placing a single polarizing sheet in place of the damaged lens will change the focal length ( maybe for the better) and will reduce the amount of light presented to the eye.

Awesome im going to pursue this route, that way i can also add a polarizer below the sample plate, do you know if extinction can be achieved with a stereo?

[Seta]

If it is a doublet or triplet lens used in humid ambient conditions humid air could maybe get inside and then condensate, I do not know if this is a common problem or even possible at all. Something similar happened to me with a telephoto lens during the monsoons even the lens was protected.

If is just a piece of glass with a filter layer( or plastic) then maybe got burnt.

[Greg Howald]

With my stereo scope I can polarize, dark field and Rheinberg. If you put polaizers inside the separated light path, they have to be positioned so they exactly match, or extinction will be in a different position from the right to left sides so be careful and have fun.
Greg

[PeteM]

. . .
If you wet both surfaces of the glass does the haze go away?
Yes for a second but as soon as it dries becomes visible.
. . .

To me, this suggests the haziness is on the surface, not something appearing inside the glass.

Could be it was there from the start, but was only noticed when you changed illumination sources.

[microb]

I'm honestly not quite sure what they are they might be some correction lenses, they are held in place by a spring clip. As I mentioned before after removing them I've noticed that I have to focus down a bit more when compared to when they were in place.

If it is a ring spring or a spring clip, then it is most likely a window or a heat filter/window. I replaced this one with a (https://www.microbehunter.com/microscop ... f=5&t=8487) I had made:
https://www.microbehunter.com/microscop ... f=5&t=8988

I used a spectrometer to check the transmission so I could match it.

[Plasmid]

I'm honestly not quite sure what they are they might be some correction lenses, they are held in place by a spring clip. As I mentioned before after removing them I've noticed that I have to focus down a bit more when compared to when they were in place.

If it is a ring spring or a spring clip, then it is most likely a window or a heat filter/window. I replaced this one with a (https://www.microbehunter.com/microscop ... f=5&t=8487) I had made:
https://www.microbehunter.com/microscop ... f=5&t=8988

I used a spectrometer to check the transmission so I could match it.

Thank you , that appears to be the their function, i looked through the thread, but couldn't find a link to the supplier, would you mind sharing their page and or contact?
Question...being uv absorber of some sort, is it something that is bound to degrade over a shorter period of time related to usage? Probably worth to order a couple of sets then?

The Lights in question, whether they made it more visible or they actually accelerated the problem I'm not quite sure.

[microb]

I'm honestly not quite sure what they are they might be some correction lenses, they are held in place by a spring clip. As I mentioned before after removing them I've noticed that I have to focus down a bit more when compared to when they were in place.

If it is a ring spring or a spring clip, then it is most likely a window or a heat filter/window. I replaced this one with a (https://www.microbehunter.com/microscop ... f=5&t=8487) I had made:
https://www.microbehunter.com/microscop ... f=5&t=8988

I used a spectrometer to check the transmission so I could match it.

Thank you , that appears to be the their function, i looked through the thread, but couldn't find a link to the supplier, would you mind sharing their page and or contact?
Question...being uv absorber of some sort, is it something that is bound to degrade over a shorter period of time related to usage? Probably worth to order a couple of sets then?

The Lights in question, whether they made it more visible or they actually accelerated the problem I'm not quite sure.

Sure. I can look. It was over a year ago, so I'll have to hunt through some files.

But first, you should find out the dimensions and the transmission spectrum of those windows. If you send me one, I can return it back to you with a transmission graph from my Ocean spectrometer. Given the diameter and thickness, maybe there is a standard option available. If they have a very faint blue tint, they are probably the KG(1/3/5) glass mentioned in the thread. If you switch your lighting to just LEDs, you could then safely switch to something like BK7 glass. Those windows are available at various sizes from lots of places, ebay and https://www.surplusshed.com/category/Optical_Windows.

[Voyager-1]

This may do the job on the lens.
Have been cleaning fungus and/or mold off camera lens with Hydrogen Perioxide with great success over the years.
With that said, you may want to try using it since you mentioned that it disappeared when wet and then reappeared when dry.
Here is a video on youtube, it is rather long 1/2 hour, check out the lens at 1minute 30 secs into the video for what it looks like at first.
Then jump forward to 14 minutes, where he starts the cleaning. (In between these times he takes the lens apart).
I have no affiliation with mikeno***, he just presents as it is, and adds a little dry humor along the way.
I use Hydrogen Peroxide Topical Solution 3%. Sold everywhere and is cheap. Just make sure to use lens cleaning tissues to not scratch surface.

https://www.youtube.com/watch?v=5B-LfYakZ-Y

V

[Placozoa]

. . .
If you wet both surfaces of the glass does the haze go away?
Yes for a second but as soon as it dries becomes visible.
. . .

To me, this suggests the haziness is on the surface, not something appearing inside the glass.

Could be it was there from the start, but was only noticed when you changed illumination sources.

I agree, sounds like its not internal.

I DID have this problem when I switched to leds. It turned out it was a thin film of oil on a lens that the leds made more visible. I cleaned it with 99% isopropyl alcohol and... Nothing, still there. I cleaned it 4 more times with the isopropyl, fresh pure cotton (not q-tips) swabs each time and light pressure and it was fine. Whew! I just use blue windex now, works way better.

[microb]

I DID have this problem when I switched to leds. It turned out it was a thin film of oil on a lens that the leds made more visible. I cleaned it with 99% isopropyl alcohol and... Nothing, still there. I cleaned it 4 more times with the isopropyl, fresh pure cotton (not q-tips) swabs each time and light pressure and it was fine. Whew! I just use blue windex now, works way better.

Acetone is effective at dissolving oils and plasticizers that can stuck on surfaces.