Author Topic: ZnSe lenses on Ebay (Read 20737 times)

havewattwilltravel · « **on:** August 16, 2018, 06:59:03 pm »

So what's the story on the ZnSe lenses on Ebay, specifically for augmenting cameras like the Flir Ex for PC board work?

Specs are comparable across a broad range of prices, except for maximum wattage.

Is the $80 200W US lens twice as good as the $15 100W Chinese one?
(The $150 US lens actually has better specs.)

My experience from Chinese products is that "consistent quality" is a Japanese concept, and the Chinese hate the Japanese, so that the variations from the same supplier for the same product are as much as the variations between suppliers.

In the end, it's all a crap shoot and the house usually wins.

Fraser · « **Reply #1 on:** August 16, 2018, 07:49:01 pm »

Most, if not all, ZnSe lenses manufactured for laser engraver use are not intended to produce a low distortion optical image when used in thermal imaging. Reputable manufacturers of these lenses even state this on the datasheet.

There are high performance ZnSe lens elements from companies such as Edmunds Optics who specify the elements performance.

In practice, almost any ZnSe lens used in laser engravers will work as a decent enough close up lens. The low resolution of the thermal cameras is often forgiving of the lesser optical performance of such lenses.

I suggest you purchase a suitable lens from China for around $20 and see if it meets your needs. A high optical performance ZnSe lens with low distortion will cost you around $150 in the USA.

Fraser

Fraser · « **Reply #2 on:** August 16, 2018, 07:53:38 pm »

Here is a reputable lens manufacturer. Note their comment in such lenses being suitable for non critical imagine quality applications.

http://www.iiviinfrared.com/CO2-Laser-Optics/plano-convex-lenses.html

The same company can supply excellent optical quality lenses for IR imaging using various materials, including ZnSe.

http://www.iiviinfrared.com/IR-Thermal-Imaging-Optics/ir-thermal-imaging-lenses.html

It all comes down to the actual imaging quality required.

Fraser

Fraser · « **Reply #3 on:** August 16, 2018, 08:02:13 pm »

Note. Power rating of the lens has little to do with optical quality. Transmission is never 100% so losses have to be managed in the lens design when used with a high powered laser.

Fraser

eKretz · « **Reply #4 on:** August 16, 2018, 08:12:51 pm »

I would watch eBay and any other sites for germanium lenses too. There are bargains now and again. I managed to snag a huge coated germanium close-up lens that fits snugly right into my rubber focus grip on my E40 for peanuts.

Fraser · « **Reply #5 on:** August 16, 2018, 08:17:13 pm »

With Germanium lenses, just be sure they are coated for LW and not SW/MW as a SW or MW only lens is useless on a LW camera.

Fraser

DaneLaw · « **Reply #6 on:** August 16, 2018, 08:19:51 pm »

Quote from: eKretz on August 16, 2018, 08:12:51 pm

I would watch eBay and any other sites for germanium lenses too. There are bargains now and again. I managed to snag a huge coated germanium close-up lens that fits snugly right into my rubber focus grip on my E40 for peanuts.

A picture and a price would go a long way as the concept of "huge germanium lenses" varies greatly from one person to the next and not least "I got it for peanuts" which also varies a lot from one to the next and difficult to put into perspective.

--

I pick one of the ZNSe a few months back, it costed 8bucks (USD) delivered with a focal length listed at 50mm.

I get this level of makro from a budget-viewpoint.(Seek Pro FF iOS 290USD + 8USD ZnSe FL 50mm)

Item..

havewattwilltravel · « **Reply #7 on:** August 16, 2018, 09:17:01 pm »

I'm not sure which line on their website tweaks me more, that their lenses are available in "diamond-like coatings" or that most of them are thorium-free.

Now I'm not sure whether to take out a mortgage or buy a Geiger counter before continuing.

eKretz · « **Reply #8 on:** August 16, 2018, 09:31:47 pm »

Sure, no prob. Lens is about 60mm O.D. and focal length around 100mm. Price was $40 + shipping through an eBay "best offer." Don't have any sample images right now, they're still in the camera. Will post a few later.

CatalinaWOW · « **Reply #9 on:** August 16, 2018, 09:57:23 pm »

When I retired several years ago "diamond like coatings" was an attempt at accuracy in describing vapor phase deposited polycrystalline diamond coatings. The processes used didn't result in diamond crystals even approaching the coating thickness, but they were harder and more wear resistance than many other options. Similarly thorium flouride is used in some coating designs. The quantities used are minuscule and thorium is not highly radioactive. The thorium risk is almost entirely in the manufacturing process, with very little risk at the point of use of the optics. Some sources estimate that the radioactive dose from using these lenses is about 1/600 of the natural background level everyone is exposed to.

A knee jerk reaction against these terms will cause you to miss some good deals and will not protect your health in any measurable way.

eKretz · « **Reply #10 on:** August 16, 2018, 10:26:41 pm »

The coating is "diamond-like carbon" and it is probably one of the most durable coatings there is. However, it doesn't have the highest transmission of the available coatings. I read a quite interesting university study of some of the iterations of DLC as they were created, they have got it refined to a pretty high level nowadays.

KE5FX · « **Reply #11 on:** August 17, 2018, 12:38:59 am »

Hacked E4 (320x240):

Hacked E4 with lens from https://www.ebay.com/itm/321078811086 (19 mm ZnSe, unfortunately I don't recall the focal length):

The smaller components in this screenshot are 0402 (US).

Checked lens with Geiger counter with alpha window, no radiation detected.

havewattwilltravel · « **Reply #12 on:** August 17, 2018, 03:42:40 am »

Thanks for posting those. That's a really impressive level of detail. It's also very moving, in a way, to be able to see the heat rather than just running an equation that predicts it.

Next question: what about meniscus versus plano-convex? Is the former better than "a type of mudbrick used by the ancient Sumerians" (another definition according to Wikipedia)?

With a high focal length (50mm-100mm), I'd be tempted to integrate the macro lens mount into some kind of adjustable tripod or camera holder. While I can't dance, I can shake. Given that my normal photography is at best impressionistic, I doubt if I could create anything more than orange smears if holding the camera in one hand and a board in the other. Kudos on making your dexterity roll.

Perhaps it's a good enough excuse to buy an arduino CNC board to scan the target...oh, such potential for wasting time and money!

Fraser · « **Reply #13 on:** August 17, 2018, 10:50:02 am »

Think of the close up lens as little different to wearing reading glasses. It just converts the focal length. With reading glasses we tend to see meniscus lenses used and they would be my first choice. Sadly such lenses are not usually used for laser engravers so they are less common and more expensive. Optical performance will, however, be better. Laser engravers use Bi-Convex and Plano-Convex. Both work fine for Close-up PCB inspection.

For greater lens performance, you sadly have to spend a lot more money. If a cheap ZnSe lens is scratched or damaged, it is no great loss and easily replaced. The ZnSe lens also acts as a lens protector for your very expensive thermal camera lens. When working very close to a PCB, say 25mm, it is easy to knock into a sharp edged heatsink or chassis part.

Fraser

eKretz · « **Reply #14 on:** August 17, 2018, 07:55:19 pm »

It really isn't difficult to get clear images with the close-up lenses handheld. The lenses on these cameras are almost always something like f/1 so they don't need much time at ALL to take a picture. On a very far subject with a tele lens you might want to use a tripod.

eKretz · « **Reply #15 on:** August 18, 2018, 11:46:55 pm »

The lens I posted a photo of above is a meniscus lens. Here are a couple images form my E40, the first image with the stock lens focused as close as it can manage, and the other of the same board with the close-up lens as close as it can focus. Do note that I didn't bother squaring the lens with the subject, so focus is only optimal in the area of interest due to very shallow DOF.

DaneLaw · « **Reply #16 on:** September 17, 2018, 02:56:34 pm »

Hi guys..

Im a littlse unsure, hence ZnSe and GaAs lenses and focal length..
Usually its ZnSe there are the most affordable alternatives..particularly the orange china ones, hence the more yellowish socalled USA-ones there seems to have better purity.
Already got a ZnSE at 12mm 50mm focal, and would like some more lenses and not least in different material like GaAs and perhaps ¨different focal length sizes to see charstica and pro and cons and perhaps incoherent with each other.

Got an offer for 20mm GaAS with a focal length af 10.1cm. (4") 15USD delivered but I reckon I could change it to 1.5" 3.8cm if that was a no brainer for macro on IR, but Im unsure about GaAS as a whole..
when its macro you have in mind, then it would make the most sense to go for the smallest focal length, correct? as a supplemented macro-lens like the above with a focal length at 10.1cm 4" would not be much more then what the native thermal lens in the Seek pro can perform in the closest turnpoint by itself' or are there some benefits with going for higher focal length and perhaps each fitted lens leverage each other...

How does a GaAS lens stack up as an macro lens in regards to ZnSE? I can see the that Gallium Arsenide GaAS transmits over 40% between 2-15µm while ZnSE about 50% between 0.4 -12μm before dropping off to zero transmission around 15μm and Germanium transmits over 45% between 2-14μm.
So GaAs is the lowest of the bunch, but how does it hold up in practice.
Thx for any info..

Fraser · « **Reply #17 on:** September 17, 2018, 03:35:19 pm »

A good quality ZnSe or ZnS lens element is an excellent performer. Excellent transmission but a little soft so easily scratched.

GaAs also transmits well at LW and is a harder material, so less easily scratched.

With your transmission figures you need to consider the AR coating applied to the lens surfaces. With no AR coating your figures are nominal, but you should be looking for lenses that are AR coated for LWIR as their transmission is far higher.

I have both GaAs and ZnSe lenses and I recommend ZnSe for your intended use if suitable AR coated Germanium is not available or too expensive.

For info ZnSe and ZnS are to be found in professional lenses but normally behind the protection of a Germanium Objective (not in every case though)

Remember that thermal cameras are relatively low resolution devices and more forgiving of less than perfect optics in many cases. PCB inspection often does not need perfect lens performance due to the nature of the targets.

Using the original camera lens set to close-up focus, if possible, is better than using a supplementary lens. You could even consider a close-up extension tube for the camera lens to provide closer focus ? It need not be very long, a few Millimeters at most. The SEEK lens mount is not that easy to work with however.

Fraser

DaneLaw · « **Reply #18 on:** September 20, 2018, 07:21:55 pm »

Thx for your feedback..Im im not sure what kind of coating this one carries.it states 0.5% pr surface for AR coating.
Most of these lenses are not headed for thermal infrared pictures but mostly centered to focal C02 lasers and the sellers, sadly don't know jack, as these usually just wholesalers, placing an order at third party on my behalf.

But its a 20mm GaAs at 15 USD delivered with a focal length at 4" 101.6 mm.
I can see he also has them in 1½" and 2" and 3" focal length..(so I reckon I could change it for a lower focal length if that was the obvious sum)
and I already have a ZnSE (cheap China orange version in 50mm FL and I reckon for variety purpose I would mix it up with a wider FL to see if there was any gain there, but on the other hand 101.5mm focal length would more or less be around the native lens in Seek pro as it seems to focus down to relative 10 to 15cm at closest point, so any gain for thermal-macro on a GaAs at 10.16CM FL?' here it would likely make more sense to go with the smallest focal length possible on these GaAs lenses' or ??)

But been pretty impressed with my cheap 8USD 50mm focal length ZnSE lens and its macro-ability and I love to fool around with wavelengths in different laser'diodes and here many of these lenses have wicked abilities to pass some wavelength and block others and so forward, not least ZnSE there are willing to pass high NM green and up, like yellow and red etc, but completely blocks blue and violet and partly low'end'nm green wavelengths...
https://imgur.com/a/xipfTdn

What you reckon' any info to sense if this GaAs lens will be doable to thermal macro?? or is it a luck of a draw if it got the useable LWIR coating but then again 90% clear aperature 10.6um.

Fraser · « **Reply #19 on:** September 20, 2018, 07:39:38 pm »

That lens will work fine

Fraser

Vipitis · « **Reply #20 on:** September 20, 2018, 09:17:38 pm »

Can you share the sellers eBay shop? Because Laserlands was previously mentioned as reputable but has no lenses offered the last time I checked.

DaneLaw · « **Reply #21 on:** September 21, 2018, 01:16:07 am »

Sure..
It was CloudRay Laser.
https://www.cloudraylaser.com/
Ebay.
https://www.ebay.com/usr/cloudray-laser?

Pinkus · « **Reply #22 on:** October 04, 2018, 09:28:26 am »

May I ask your opinion?
I decided finally to get a ZnSe lens for my Exx to allow a closer focus / higher magnification. However I do not need a huge magnification, 2x is fine for me.
I am afraid a 20mm lens might be not large enough, as the original lens is already approx. 25mm (see pic attached). A 25mm lens probably gets a sharper image at the corner.
Thus I think a 25mm lens with a focal length of 100 to 150mm would be correct.
Would this lens here https://www.ebay.com/itm/152310493227 with 25mm diameter and 101mm focal length be OK? 33$ incl. shipping sound like a decent price for a 25mm lens.
Thanks!

Fraser · « **Reply #23 on:** October 04, 2018, 09:51:57 am »

I have not used a ZnSe laser lens on my Exx series as I have larger diameter Inframetrics Germanium lenses. You are quite correct, a 20mm diameter lens would appear too small for use with an Exx series camera. You need to consider the objective diameter plus the FOV. A lens of equal diameter to that fitted in the camera would need to be positioned very close to the objective to reduce distortion and vignetting. A risky practice as physical contact with the cameras objective is highly undesirable ! Even a 25mm diameter lens may not avoid vignetting due to the cameras FOV. It would need to be close to the objective, as stated. My supplemental Close up lenses are 50mm diameter but such are hard to find at reasonable cost, even if ZnSe rather than Germanium.

You may have to live with some vignetting, but that may still be acceptable for PCB inspection.

Fraser

Pinkus · « **Reply #24 on:** October 04, 2018, 10:40:57 am »

Thanks Fraser,
Indeed, lenses with a diameter of 38mm or 50mm are quite expensive.
I now just bought the 25mm lens with 101mm FL and will report the results after arrival in a few weeks.
In the meantime I have time to plan of a decent lens holder for the Exx.

Fraser · « **Reply #25 on:** October 04, 2018, 11:46:20 am »

The Exx has a convenient rubber lip extending around the front of the lens. This acts as a very effective grip ring around any disc shaped adapter you might make. Some thing like the original 3D printed combined disc and cone adapters used with the E4 comes to mind.

There is also the official supplimental lens mount option. You remove the silver lens trim and fit a bayonet mount lens holder in its place. Helpfully some kind person has already designed and published such a bayonet mount adapter for a 20mm supplimental lens. It was intended to be used with a different camera series but fits the Exx series perfectly as FLIR use a common mount between the series.

I will add the thingiverse URL for the adapter in a minute.

Fraser

Fraser · « **Reply #26 on:** October 04, 2018, 11:48:55 am »

OK, here is the bayonet mount close up lens adapter I mentioned and also the link to the original E4 lens adapter.

https://www.thingiverse.com/thing:1078735

https://www.thingiverse.com/thing:187166

Fraser

Fraser · « **Reply #27 on:** October 04, 2018, 11:58:03 am »

As can be seen in the example pictures in the Thingiverse bayonet mount project, the 25 degree FOV of the cameras fixed lens, combined with positioning of the 20mm supplimental lens in front of it means little vignetting is visible in close up imaging. Certainly good enough for PCB work. The 25mm will be better but you will need to modify the 3D design to accommodate it. You could buy a 20mm lens as well to play with as they are very affordable

I printed the bayonet mount lens adapter in ABS and it fits my E40 perfectly. I am using that design as the basis of an adapter I need for a FLUKE bayonet mount X2 telescope supplimental lens. Just need the time to tinker with it.

Fraser

Uho · « **Reply #28 on:** October 21, 2018, 10:38:44 am »

Recently, at the request of a friend from the thermal imaging forum made a universal holder for macro and body lenses under the FLIR E series. Holders macrolens for FLIR you can find several types of on the Internet. They are all United by the principle of fastening - due to friction. But it's not very reliable. When shaking the lens may fall out. They fight very easily, and the price is not small. And on this principle it is impossible to fix heavier multi-lens lenses. What I wanted to achieve:
1. Reliability of lens mounting.
2. Universality.
3. The opportunity to obtain low distortion of the image.
If you want a large magnification then the idea of using a single lens doesn't work very well. The photo shows image distortion if you use an f25mm selenide lens. Two lenses F38.1mm is better work there. Less distortion. The different lenses can be set in different sequences to get the required magnification in macro mode from 1x to 8x. More expensive germanium lenses with a maximum diameter of 28 mm will provide a low level of distortion (spherical and chromatic aberration and distortion of the "pillow" / "sheet"), a better signal / noise ratio. Cheaper lenses made of zinc selenide of small diameter will allow you to get a budget option with low cost optics, but are still used for simple works. Thus, the adapter provides maximum flexibility in the use of existing lenses, cheaper or more expensive.
Where do we need such holder and macro lens, for example, in the field of medicine - photo palm. Macro lenses For the use of electronics diagnostics-photo phone. Well, in addition to this, you can install a telephoto lens in such a holder.
The plastic part of the holder on a 3D printer was printed and then polished on a lathe. Holders lenses sharpened then polished and anodirovanie.
A short video about the device holder can be found here
https://youtu.be/UG-XuUb1GrU

KE5FX · « **Reply #29 on:** October 21, 2018, 08:51:14 pm »

Quote from: Uho on October 21, 2018, 10:38:44 am

Recently, at the request of a friend from the thermal imaging forum made a universal holder for macro and body lenses under the FLIR E series.

That looks great. Are they selling those? I've been using copper tape to mount a ZnSe lens on my E4, and it would be nice to have an option for easier insertion/removal.

KE5FX · « **Reply #30 on:** October 30, 2018, 12:24:15 am »

Seriously. Somebody sell me something.

Uho · « **Reply #31 on:** November 01, 2018, 12:31:19 pm »

I can make a holder for you. With one lens tube the price of $ 50 does not include shipping.

KE5FX · « **Reply #32 on:** November 01, 2018, 11:24:33 pm »

Quote from: Uho on November 01, 2018, 12:31:19 pm

I can make a holder for you. With one lens tube the price of $ 50 does not include shipping.

PM sent.

Pinkus · « **Reply #33 on:** February 20, 2019, 11:16:55 pm »

A while ago I asked Fraser for some advice regarding the correct ZNSE lens size/ focal lenght for building a macro lens (which he gave me).
Finally I purchased a ZNSE lens with a focal length of 100mm and a diameter of 25mm for my Flir Exx. Remark: for the Exx you need the 25mm diameter - do not purchase a smaller one!
Though an easy mounting was not possible, so I buildt a 3D printed holder for it. This took a while, but I had now time to finish it.

I am attaching a few photos and also the STL file for it, so you can print your own.
The holder consists of the bayonet clasp for the camera and an included lens holder with a separate ring. When printed, just insert the lens, press the ring on the front and you are all set. With the two small ball shaped handles you can easily insert/remove and rotate the unit.
Credits go to Kaji_fi who designed the bayonet (the lower 1.5 mm of the part) for a Flir T-series and that I borrowed for this.

I am also attaching a comparison between the regular lens and the added ZNSE. You are able to get much closer and by using the focus ring of the camera you are able to select the distance you like and then use the focus ring to focus. By this you have a kind of zoom-feature. This is now way better for working on electronics!
I purchased the lens here (I am not related to the seller): https://www.ebay.com/itm/152310493227; though it took approx. 8 weeks until it arrived. Costs: $33 including shipping.

Fraser · « **Reply #34 on:** February 21, 2019, 12:09:34 am »

@Pinkus

Excellent work

I shall print your lens holder and use it myself

I just ordered the 25mm lens from the same sourc3 as you. I paid the extra $2 for standard postage. We shall see how long it takes to get to the UK.

I am going to use that same Kaji-Fi mount design for my lens mount adapters. Just need to find the time to get back on Sketchup.

Thanks for sharing your design here

Fraser

Fraser · « **Reply #35 on:** March 02, 2019, 12:41:00 pm »

The 25mm lens arrived with me in the UK from China today. 9 days for delivery. That is a pretty good transit time so it was well worth paying the extra £2 for ‘Standard’ shipping rather than ‘Economy’

Fraser

richnormand · « **Reply #36 on:** March 02, 2019, 08:48:30 pm »

Different solutions for different people.

I needed to look and take pix close up on a circuit board with my SeekThermal. I used a cheap eBay ZnSe (for 10um laser stuff) and a pool noodle (with a hole in the middle) for a friction fit to the camera.
Works perfect for my needs.

Uho · « **Reply #37 on:** March 02, 2019, 09:07:03 pm »

I also thought that foam rubber holds the lens well. Result on the photo. Almost $ 50 in the trash. After that, I only make a good mount.

Gyro · « **Reply #38 on:** March 02, 2019, 09:30:14 pm »

Sad to see one end up like that.

My masking tape solution isn't much more secure. Luckily I rarely need to 'fit' it. Unfortunately the TG130 has no convenient mounting points.

https://www.eevblog.com/forum/thermal-imaging/flir-tg130-review/msg1388901/#msg1388901

richnormand · « **Reply #39 on:** March 02, 2019, 09:30:35 pm »

Ouch!
Sorry to see that Uho.

I guess I have been lucky up to now.

Never had an issue over the years and it was also used several times by grad students. The fit is quite stout and the Seek camera lens baffle is slanted inwards towards the insides and the lens is the exact diameter of the baffle exit.
At the end the fit is quite strong. I have no doubt should I drop the assembly it could detach. Fortunately all the work I do is over a soft anti-static mat of the bench. (Keep fingers crossed).

But at the end of the day I should consider a proper adapter. This idea was initially a "quick one-of" a few years ago and since I am using it regularly I should make it good. (Inner voice... need to justify getting a 3D printer,,,)

Fraser · « **Reply #40 on:** March 02, 2019, 10:16:28 pm »

Uho,

Nice mount

Fraser

KE5FX · « **Reply #41 on:** April 05, 2019, 05:55:07 am »

Quote from: Uho on October 21, 2018, 10:38:44 am

Recently, at the request of a friend from the thermal imaging forum made a universal holder for macro and body lenses under the FLIR E series. Holders macrolens for FLIR you can find several types of on the Internet. They are all United by the principle of fastening - due to friction. But it's not very reliable. When shaking the lens may fall out. They fight very easily, and the price is not small...

I just received one of these lens holders from Uho, and it's awesome. Very well made. It is now much easier to install and remove an external lens from my E4. Highly recommended for anyone who is tired of messing around with tape.

Uho · « **Reply #42 on:** April 05, 2019, 07:28:06 am »

Thanks for the feedback.

I was glad to help. If anyone needs holders please contact us.

frogg · « **Reply #43 on:** August 02, 2019, 02:37:43 pm »

This is great info...

Out of curiosity, has anyone had any success with building a telephoto adapter using a pair of plano-convex lenses? Say a 4" FL front and 1" FL rear?

Uho · « **Reply #44 on:** August 07, 2019, 08:48:40 pm »

I recently made a lens holder for euzer. This is a slightly modified macro lans holder for Flir E. I made a short video with English subtitles.

https://youtu.be/6_EUN7DSm9Y

TE-V1 · « **Reply #45 on:** August 16, 2019, 02:37:36 am »

Quote from: DaneLaw on August 16, 2018, 08:19:51 pm

Quote from: eKretz on August 16, 2018, 08:12:51 pm
I would watch eBay and any other sites for germanium lenses too. There are bargains now and again. I managed to snag a huge coated germanium close-up lens that fits snugly right into my rubber focus grip on my E40 for peanuts.
A picture and a price would go a long way as the concept of "huge germanium lenses" varies greatly from one person to the next and not least "I got it for peanuts" which also varies a lot from one to the next and difficult to put into perspective.

--

I pick one of the ZNSe a few months back, it costed 8bucks (USD) delivered with a focal length listed at 50mm.

I get this level of makro from a budget-viewpoint.(Seek Pro FF iOS 290USD + 8USD ZnSe FL 50mm)

Item..

Assuming you have a thermal camera that has interchangeable lenses, then there are other ways to do thermal macros that don't require additional lens elements at all, reducing further losses. For instance, simply moving your lens further away from the camera...In other words, using an extension ring, or even a macro bellows, between your thermal camera and the thermal lens. My Thermal Expert TE-V1 has a Schneider 00 mount (M25 x 0.5mm), and I just discovered an M25 x 0.5mm to M42 adaptor on ebay for under £10 with free postage.
This will allow me to fit my current Umicore 19mm f1.0 Thermal lens onto the front of my various old 35mm film format M42 extension tubes or my old macro bellows. The tricky bit is finding an adapter that allows the bellows to fit onto the camera...That's not so easy to obtain and I may have have to make a custom adaptor for the job.

Uho · « **Reply #46 on:** August 17, 2019, 01:46:33 pm »

Hi! Many owners of thermal imagers ask which lens is best for macro. And still they buy the cheapest lenses. The photo is not the cheapest lenses. Usually they buy even cheaper. But I don’t buy them after the tests anymore. The difference in price is almost doubled. Image quality is also different. In the thermal range as well. On high-resolution thermal imagers, this is visible. If you need a good image you will have to buy a CVD lens.
I'm talking about lenses designed to work with a CO2 laser. I have Thorlabs optical lenses. This is a different level of image quality. The price is also an order of magnitude higher.

Uho · « **Reply #47 on:** August 17, 2019, 08:19:03 pm »

In some cases, I use GE lenses. At the same focal length, distortions such as the fisheye effect are less than half. When compared with lenses ZNSE.

Ultrapurple · « **Reply #48 on:** September 06, 2019, 11:48:06 am »

On the Therm-App Flickr group, Hagrid Rubeus has 3D printed a holder for a small ZnSe lens for the Therm-App camera.

No word yet on how well it works, the sensitivity or image quality, but there is a discussion starting about it here.

meanie2 · « **Reply #49 on:** September 29, 2019, 12:03:45 pm »

https://www.phonereco. com/macro-lens-for-seek-camera/

_Wim_ · « **Reply #50 on:** November 03, 2019, 09:11:13 pm »

This seems like a nice lens for only 40$ including shipping:

https://www.ebay.com/itm/CO2-LASER-LENS-OPHIR-61982-FinnPower-PrimaPower-055491-USED/174070321640?hash=item28876651e8:g:p5wAAOSwCX5dqzDA

Specs:
ZnSe Meniscus Lens Ophir (Newport)
Diameter: 1.5"
Focus: 5"

Probably replaced due to thermal lensing becoming too high, but I would think this is still useful as a macro lens for a thermal cam, especially at such a low price. I bought one to give it a try.

_Wim_ · « **Reply #51 on:** November 14, 2019, 09:02:16 pm »

Lens arrived. It does show some discolouration that is not due to reflection in the coating but probably due to heat from being exposed to high power CO2 laser beam. This does not seem to affect the working at a first preliminary test. Zoom effect can be seen from the 2 pictures at minimum zoom distance of the flir E30 (with upgrade to E60).

Uho · « **Reply #52 on:** March 28, 2020, 01:41:26 pm »

Making a macro lens holder for Seek thermal from metal. In the video I showed the main stages of manufacturing. It turns out a reliable and beautiful holder.
https://youtu.be/bVIwKN6C8Xg

Fraser · « **Reply #53 on:** March 28, 2020, 02:20:02 pm »

Uho,

You have always been a master of metal turning

Beautiful work

Fraser

Fraser · « **Reply #54 on:** March 28, 2020, 02:33:19 pm »

A couple of comments that I hope will be helpful......

When mounting the fragile lens element it is important to not apply point source pressure to it as this can promote a fracture, especially if the holder changes temperature. To avoid this it is important to have a small clearance gap around the lens element outer edge and to mount it between two soft ‘washers’ if it is not being fixed in place with a mastic compound. The ‘washers’ may be nitrile ‘O’ rings or common fibre plumbing washers. The expansion gap and mounting rings/washers ensure that no point pressure is applied to the lens element. It is possible to use very thin soft washers or ‘O’ rings so they are often not visible when installed. The cross sectional profile of a Plano Convex or Meniscus lens element is not well suited to being clamped ‘bareback’ between metal surfaces.

When making a clamping screw that will impact upon a soft or easily scratched surface, like a lens barrel, it can be a nice idea to use a slightly larger finger screw diameter, centre drill it’s tip and make a nylon insert tip (top hat shaped) that provides the required pressure but not the potential scratching to the clamped surface.

Fraser

Fraser · « **Reply #55 on:** March 28, 2020, 03:07:17 pm »

Examples of pre made nylon tipped finger screws

Fraser

Uho · « **Reply #56 on:** July 01, 2020, 04:40:43 pm »

I made a macro lens holder for the Flir I series thermal imager. Although these thermal imagers are no longer manufactured, many have them. My solution to the lens holder can be seen in this video.
https://youtu.be/59f501u4_CU

talrove · « **Reply #57 on:** September 15, 2020, 05:22:47 pm »

Uho adapted his design to fit my FLIR i7 thermal camera, with fantastic results.

It fits the camera securely and by using two focal length lenses either by themselves or stacked, I am able to achieve several magnifications. At the highest magnification, the field of view is approximately 7 mm across, allowing for sub-millimeter resolution.

0x7D · « **Reply #58 on:** June 06, 2021, 04:40:30 am »

Hi Folks,

Here's my contribution of a 3D printable lens holder for 25mm ZnSe/GaAs lenses from Ebay. The design is very similar to @Pinkus's design, but is modified a bit to be printable without supports and is threaded to allow for glueless assembly.

I sourced my 25mm (127mm focal length) ZnSe CVD lens for $35 from https://www.ebay.com/itm/174413573953 which shipped from US and arrived in 3 days. Quality is excellent and I'm quite happy with the results.

STLs are available at https://www.prusaprinters.org/prints/68585-flir-exx-25mm-lens-adapter and the original design files can be found in my post at https://0x7d.com/2021/flir-exx-accessories/.

Fraser · « **Reply #59 on:** June 06, 2021, 12:55:59 pm »

Welcome to the forum

Very nice work

I will set my 3D printer to work making this very neat lens holder

Fraser

_Wim_ · « **Reply #60 on:** June 07, 2021, 04:52:57 pm »

Quote from: 0x7D on June 06, 2021, 04:40:30 am

Hi Folks,

Here's my contribution of a 3D printable lens holder for 25mm ZnSe/GaAs lenses from Ebay. The design is very similar to @Pinkus's design, but is modified a bit to be printable without supports and is threaded to allow for glueless assembly.

I sourced my 25mm (127mm focal length) ZnSe CVD lens for $35 from https://www.ebay.com/itm/174413573953 which shipped from US and arrived in 3 days. Quality is excellent and I'm quite happy with the results.

STLs are available at https://www.prusaprinters.org/prints/68585-flir-exx-25mm-lens-adapter and the original design files can be found in my post at https://0x7d.com/2021/flir-exx-accessories/.

Very nice! I see on your blog that one of the items "next on your list" is a tripod mount. I have been using this one (not my design) and am very satisfied by it: https://www.thingiverse.com/thing:2822096

redbook · « **Reply #61 on:** November 17, 2021, 04:26:15 am »

Hi,

I just found this thread. May I ask for some suggestion.
I need a macro lens for my P2 Mini camera.

https://www.infiray.com/P2.html

This YouTube clip shows a nice lens holder.

https://youtu.be/YOTNMfkEblw

I wonder what focal length to choose. Is it the distance from the working object to the lens ?

Does the distance of the lens to the sensor matter ?

Thank you.


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Author Topic: ZnSe lenses on Ebay (Read 20737 times)

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