Flir Scout LS64 teardown - Page 1
Forum section: electronics / general

author: Philtron
author_rank: Newbie
timestamp: July 06, 2019, 12:51:20 am
content: Hi all,I could not resist and took an expensive gamble in an auction for a LS-64 with a blurry image. I was hoping it is just defocused - wrong. :-(After unpacking it was obvius, the coating of the 32mm front element was gone and the surface is very rough. No way to get it back.The surface through my microscope looks grainy and rough.Nowhere near optical surface finish. What has happend? I do not understand what could harm the Germanium and its coating this bad. Or is it something else? Unfortunately i have no way to find out, the lens will have to be replaced. :-(Testing the Imager i found, the shutter was clicking but not moving. It was substracing whatever it saw during the darkfieldcompensation from the actual images. The housing of the shutter was bent because some specialist screwed the lens in too far. No, not me... ;-)I disassembled it, carefully straightened everithing under my microscope, reassembled and it works fine now. One Problem solved. :-)From Frasers brilliant posts i know, i have a Tau640 core, the sensor is bigger than the one on my Scout 240 (Tau 320). Also the shutte is just one blade in the Tau 320, the Tau640 shutter is more complicated due to space restrainments around the huge sensor.Because i was curious and couraged after reading Frasers posts, it stuffed my Tau320 Core (13mm lens) from the ScoutI 24 into the LS-64. It works perfect, seems i have more res than 240 or it is just the better Display. Not sure but the Zoom works fine.Here are some additional Pics, showing the LS-64 boards. ^To be continued....

author: bap2703
author_rank: Regular Contributor
timestamp: July 06, 2019, 05:31:09 am
content: How to clean a lens: sandblast edition

author: Fraser
author_rank: Super Contributor
timestamp: July 06, 2019, 08:55:06 am
content: The LS64 uses a VGA display panel. The PS24 was fitted with a QVGA panel.I have seen similar damage on a Germanium lens when someone Wanted to remove the damaged AR coating, thinking it would improve matters ! They used various grades of abrasive material and metal polish ! He presented the resulting mess to me for ‘repair’. Sadly such damage is terminal for the lensYour lens appears to have suffered the same treatment as I can see remnants of the AR coatingThankfully the TAU lenses are replaceable, but sadly not that common on the used market. You could contact ‘1os’ on this forum and ask if he has a spare TAU640 lens he can sell to you as he has some spare parts for some FLIR scopes. It is best to write to him in Russian as he speaks no English. Use Google Translate. He very kindly sold me a complete PS24 casing and electronics without the TAU and is a really nice reliable guy. He told me to get in touch if I had any other FLIR needs so he might be able to help you.‘1os’ has just posted in this thread......https://www.eevblog.com/forum/thermal-imaging/scout-iii-firmware/Fraser

author: Ismsanmar
author_rank: Regular Contributor
timestamp: July 06, 2019, 01:38:09 pm
content: I thought I would bid more for this Scout, but I didn't because I had recently managed to repair an A320 9Hz that I bought on eBay, from South Korea, for 550€ including shipping and taxes. And the quality of the video that its sensor gives with its 25μm sensor pixels is much more than I expected.The truth is that if this Scout had radiometric capabilities I would have been interested even for more than what you paid for, but for the 750€ that has cost you, I do not know if it is worth the higher resolution and framerate. And just the fact that the seller did not take direct photos to the lens should have given you some clue, when in most ads thermal cameras is the first thing that is displayed. I am you and I would try to return it, no matter how much the seller has listed it as for parts or not working.

author: Fraser
author_rank: Super Contributor
timestamp: July 06, 2019, 04:08:38 pm
content: I believe I was also tempted by this very unit as it was stated as being in The Netherlands so no VAT for me to pay. I did not bid because of my promise to myself to behave and stop buying thermal camerasI feel very sorry for the OP as I thought similar to him. I suspected that the unit had been dropped and either the focus had jumped a thread in the impact or one of the lens elements had moved due to failure of the securing adhesive. This has happened on other cameras that I have repaired after being dropped. Thermal scopes are prone to drop damage due to their common usage scenarios. I would not have expected a destroyed objective to the extent that is evident in these pictures. I honestly cannot think why someone would take such an abrasive approach to ‘polishing’ a lens except to prove how much serious damage can be caused. Yes I have seen lenses after people have tried to clean them with inappropriate fluids and cloths but it is rare to see someone accidentally trash a lens to this degree. They must have been deliberately trying to remove the, presumably damaged, AR coating.With great effort it might actually be possible to recover the lens through very careful correct polishing and buffing but it would have quite high losses due to the lack of AR coating. Much depends upon the actual material used for the lens. It could be pure Germanium or Chalcogenide IR glass.This is one of those occasions where I have mixed feelings........I am pleased that I did not spend my limited funds on this LS64, but I am also sorry that the OP has found himself in this less than ideal position. There is the possibility of sourcing a replacement TAU lens on the secondary market. The OP needs to look at the TAU datasheet and manual to determine which lenses are compatible with the TAU640 sensor dimensions.On the seller front.... I regret to advise that all auctions that state ‘Spares or Repair’ need to be treated with great caution and expectation of some undeclared problems. The sellers are sometimes very helpful when asked for more detail of any defects that can be seen. Those that are not receptive to questions are likely people to avoid buying from. I bought a laptop that was sold as Spares or Repair just because it needed the OS reinstalling. The laptop was in like new condition and perfect in every way once the OS was reinstalled. I only found out about the OS as the reason for the Spares or Repair status when I asked the seller for a condition report.In this specific case the seller has stated that the unit was bought at auction so it may be assumed it has no known history. He states that the image does not look right and even provides sample images for inspection by potential bidders. I was considering bidding and did not consider the seller to be dishonest in the description. Not everyone is knowledgeable about thermal cameras and their optics. We cannot be certain that the seller knew the lens was trashed. I suspect it was the seller who drove the lens into the FFC flag whilst adjusting the focus ring in the hope of correcting the blurred image. When this proved fruitless it was sold on as Spares or Repair. That is a very common occurrence on eBay and not dishonest in my book. People, including me, buy faulty kit cheaply hoping to repair it for ourselves or resale. I tend to keep kit I cannot repair whereas others try to recover some of the investment via resale. Should the seller have said they tried to refocus the camera ? Maybe, but there could still have been just a loose lens element in the assembly causing the problem. He did not lie about the fault but MAY have failed to disclose his attempts at repair. That is a grey area as he may not have made the condition any worse than when purchased in his mind.The only weird thing about the auction is that the unit sold in May and was re-listed in June. This can be a non paying bidder or when someone wins a complaint case and returns the unit to the seller as ‘not as described’ or faulty. I doubt that a return would be supported in this case by eBay as the unit is ‘as described’ and the pictures are accurate representations of the units performance, or lack there-of.I hope that the OP can source a replacement lens at reasonable cost. ‘1os’ might be able to help him. Another possibility is to find another ‘generic’ lens that can be adapted to fit the TAU640. I have a Therm App lens but I do not think that is suitable. There may be other affordable lenses that are a better match. Ophir lenses have appeared on eBay recently at decent prices and datasheets reveal the illumination area behind the lens etc.Fraser

author: Fraser
author_rank: Super Contributor
timestamp: July 06, 2019, 05:11:34 pm
content: Philtron,I have sent you a PM. Please check your mailbox on the forum 🙂👍

author: Philtron
author_rank: Newbie
timestamp: July 07, 2019, 02:37:10 pm
content: Thank you Fraser!My thoughts when seeing the auction where the same. And i just could not believe, one coud "clean" off the coating and tryes to "polish" the lens using sandpaper or similar stuff.I am not familiar working with Germanium but is is nearly impossible to ruin a glass lens like this. Still i am not sure if it is Germanium. Is Ge soft?But i should have known he seller tryes to hide evidence. It is not easy in our times to take images of the item, exactely bad enough to hide a damage but good enough to show the good parts. I realized that with car auctions already. Now it seems like a universal rule to me. Pictures bad, little info -> keep out.An expensive learning event for me. :-(I will try to get a Replacement for the lens. If not a used one, i have contacts to the optical world. But i think Qioptiq will charge an arm and a leg if they can help.

author: Fraser
author_rank: Super Contributor
timestamp: July 07, 2019, 02:47:24 pm
content: I am sorry that this happened to youI have experienced the same disappointment when sellers have been “economical” with the truth !I have been burnt on cooled cameras so passed on my bad experiences with that technology via this forum in order that others learn from my errors/experience.Thank you for documenting your bad buying experience here. It cannot have been a nice experience for you and many would not wish to make it public. You have helped others to be cautious when buying such technology on eBay thoughGermanium is metal and not a super hard metal with a Mohs of 6.0. It is not soft though. It is easily scratched unless coated with a decent AR coating like Hard Carbon, that protects it as well as providing the AR function. So yes, Germanium is very easily damaged by abrasion when not protected. As to the abrasion resistance of Chalcogenide IR Glass, I have no experience of that material when it comes to damage.As a comparison of hardness.MohsGermanium = 6.0BK7 Glass = 5.5 - 6.5Hardened Steel = 7.0 - 8.0Titanium = 6.0Tungsten = 7.5Tungsten Carbide = 9.0Brass = 3.0Copper = 3.0Aluminium = 2.5 x 3.0Iron = 4.5Fraser

author: Vipitis
author_rank: Frequent Contributor
timestamp: July 07, 2019, 08:27:52 pm
content: It took me a while to understand the first image as the scout from the front and not a microscope image. It does look awful, but at least it wasn't on you to destroy a lens element. As it won't hurt, examining the lens assembly more closely might allow you to deduce the actual manufacturer and maybe even specifications for just the front element. Buying a single element with coatings and assembling it might be more expansive than sourcing a 2nd hand lens or even a whole different lens that just about fits the chassis and works with the sensor size.My experience with lenses are limited and I treat them with care now. Coatings are still magic to me. Best of luck to get that sorted.

author: eKretz
author_rank: Frequent Contributor
timestamp: July 08, 2019, 04:48:28 am
content: Man that sucks. Hope you get it sorted as painlessly as possible. Now tell us about whatever you're using for that surface profiling please! Very cool.

author: cnxunuo
author_rank: Regular Contributor
timestamp: July 08, 2019, 05:30:15 am
content: It might be worth trying to restore it, since you have a optical profiler, I would suggest getting some CeO2 optical polishing compound, and go for it. I tried it on MWIR lens and old visible light lens due to corrosion (haze inside lens, hazy image) with great success.

author: Philtron
author_rank: Newbie
timestamp: July 08, 2019, 02:08:49 pm
content: I thougt about restoring it too. Alternatively i have contacts to a lot of companies able to perform stuff like this. But unfortunately it would not bring the coating back as Fraser already mentioned. This would sacrify a lot of performance, i do not like this idea.The front element is held in place by a glued ring, i have no idea how to get it out. May be heat is the key but will the undamaged parts survive high temps?The remais of the coating seem to be very thick. I think at least 50µm. I will try to get it measured. Even if i could be sure about the coating type and had a company in mind to recoat, i think it would be very expensive.The Lens itselve could be diamond turmed, that would explain the circular structur seen in the microscope front view. The intensity map of the result page shows the Ge grain structure. The pits fit between these grains, this would be a strong sign for corrosion. But Ge does not corrode easy at room temperature.The damage seems to be bigger at the edge of the lens, so may be the corrosion creeped in from the edge and made ists way to the center under the coating.This would have been easy to see in the auction pics, so i assume someone pulld off the rest of the coating to get more unsuspicious images. Just my guess...eKretz, i am using the profiler rarely, i found it in a high-end dumpster and brought it back to live, recalibrated it on traceable standards. Everyone asks; what do you do with a sub-nm resolution surface profiler at home? I own it but use it rarely...most samples are too rough. But a neat pice of kit if you have a wafer fab at home or if you want to measure glass roughness or flatness, lapped parts, laser damage on optics etc... no such thing here but the profiler(s) :-)Unfortunately it is not suitable for form errors in spherical optics. That would reqiure the repair of a Laser Interferometer (cough, cough) and procurement of some reference optics. But these are expensive as hell, even for used ones you could buy a nice used car.If you have questions, feel free to pm me.

author: eKretz
author_rank: Frequent Contributor
timestamp: July 08, 2019, 04:19:35 pm
content: Very cool all the same. By the looks of it the lens is likely diamond turned, and that points to it being almost certainly germanium. And while it could certainly be polished up, without proper equipment you'd lose the geometry of the surface. And without the coating you'd lose most of the use of the cam without the ability to recalibrate. Even then, your S:N would be way high, so the image would be very noisy. As you've already noted, best to try to find a new lens element.

author: cnxunuo
author_rank: Regular Contributor
timestamp: July 08, 2019, 05:11:08 pm
content: A good excuse to CNC a adaptor for 50/100mm lens?Some other older 19/35mm lwir lens has long flange distance, which makes adapting easy.

author: eKretz
author_rank: Frequent Contributor
timestamp: July 09, 2019, 05:36:02 am
content: Step one would be getting the lens element out, so as to see exactly what he's working with. On that front, I've removed the front lens element from my E40, and by the description it may well be fastened the same way as the Scout. I used a very fine razor blade from a double edged safety razor (about .004" thick) to carefully remove the adhesive around the lens, working it down into the groove between lens and housing and going around the lens several times over. Then it almost dropped right out. After examining and taking measurements of the lens I cleaned it with KimWipes and acetone and refastened it in tbe bore with UV-curing adhesive.The lens fits securely in the bore at the very base and seats against a shoulder, so it is easy to get the lens back in the right place and centered. At the top of the bore, the diameter is slightly larger to leave room for whatever adhesive they used originally.

author: 1os
author_rank: Regular Contributor
timestamp: November 03, 2019, 10:58:29 pm
content: 640/512 30hz 35mm