Author Topic: Best thermal camera for $300 (Read 13007 times)

jean-paul · « **on:** February 16, 2018, 05:10:40 pm »

Hello,

I'm looking for the best thermal camera for around $300. I think the cheapest it to have an OEM core and then to use a rasperrypi/laptop for display. I don't mind spending time to make it working!

I did a small comparison of the most popular, do you have other proposals?

- Flir Lepton 3 = $240 + $40 for the breakout board = $280
Pro: 160x120 / quality seems ok for the price
Con: if you want something "portable", it seems hard to use it with windows, unless you buy https://groupgets.com/manufacturers/getlab/products/purethermal-1-flir-lepton-smart-i-o-module for $110, so $350 total

- Flir One = $200
Pro: works out of the shelves
Con : 80x60

- Flir One Pro = $400
Pro: works out of the shelves / 160x120
Con : doesn't seem reliable / a bit over budget

- Seek thermal = $250
Pro: works out of the shelves / 206x156
Con: seems noisy

Thank you,
Jean-Paul

Spirit532 · « **Reply #1 on:** February 16, 2018, 06:16:55 pm »

The Lepton3 breakout + Raspberry Pi(a clone works too) and a display could be a good option if you're willing to tinker to get it working.

What do you need the camera for? There are a few good options on the used market too, but they might not be fit for your your needs(analog video out, etc).

Vipitis · « **Reply #2 on:** February 16, 2018, 06:58:26 pm »

There are some similar projects.

You can always look for used and token stuff like flir one iPhone case and rip out the Lepton module... Those are available for 60€.

Used or broken seek pro models could be an option, or car night vision cameras if you get them to work.

Flir scout TK starts at 500€ used, and you get 160x120 non radiometric, but DDE and narrow fov with their optics of about 20°.

I don't know if framerate is a topic for you, but most Leptons you can buy are 9hz, or something like 8.6; a 30hz module with screen and optics is built by TPLogic but at a higher price point.

I think seek has some wildlife imaging devices, which use the seek core and have a screen. I don't know about pricing on those. Other companies who build thermal images for hunting like Pulsar or Leupold exceed or budget.

For firefighting cameras, used or broken, there is other people to talk about options up to 300$ here.

jean-paul · « **Reply #3 on:** February 17, 2018, 12:10:10 pm »

Hello,

Thank ou for your answers. I'd like a thermal camera mainly for building heat leakage control. So I don't mind about a slow framerate.

Here in France it's hard to find a used Seek/Flir One but it's a good idea.

So a Lepton 3 + PureThermal 1 - FLIR Lepton Smart seems the best compromise for this price range? Unless I can found something on the used market?

Thanks,
Jean-Paul

Spirit532 · « **Reply #4 on:** February 17, 2018, 02:07:57 pm »

If you don't mind looking for used gear and don't need radiometry(temperature readout), there are definitely good options out there - there are a few 320x240 cores on eBay right now that output composite. I recently picked up two FLIR Photon 320 cores with huge 35mm lenses for ~$300-ish each. Most cores just need power(usually 12-24V) and output regular composite video, also usually full-rate(20-30-60Hz), not limited to 9.

Other than that, your best bet is bodging together something with the Lepton, yes. It's lower resolution, but will be handy in seeing small heat differences if setup properly(disable the AGC, manually range it in software).
PureThermal 2 is out by the way, it's only $70 + Lepton + Shipping.

mahony · « **Reply #5 on:** February 17, 2018, 02:09:28 pm »

I would also suggest the Lepton3 + pure thermal board (probably the version with USB ~100$).

You can source a Lepton3 from broken Flir One Gen2 devices. I bought 2 of them myself for ~80€ (currently more like 100€ in europe) and ripped out the Leptons to play with them.

This way you can get an USB IR cam w/ 160x120 resolution for roughly 200$.

jean-paul · « **Reply #6 on:** February 17, 2018, 07:30:15 pm »

You are lucky to got a FLIR Photon 320 for $300! It's 2000€
And an used FLIR E4 is around 1000€.

I can't find a used Flir One Gen2 or 3 Pro here in Europe. I think I'll buy a new Lepton 3 + PureThermal 2.

Thanks for your recommandation

mahony · « **Reply #7 on:** February 17, 2018, 08:09:06 pm »

Two on eBay currently:
https://www.ebay.de/itm/Defekt-FLIR-ONE-Warmebildkamera-fur-iOS-Gerate-AA0057/152910230447?hash=item239a28f3af:g:nqwAAOSwTYxZjDPk
https://www.ebay.de/itm/Flir-One-IOS-Defekt/112817543533?hash=item1a4473196d:g:cb8AAOSwrslahd~8

I almost ordered one of the PureThermal2 but was a bit shocked by 45$ shipping cost - seems to be GroupGets standard, also for other products.

Fraser · « **Reply #8 on:** February 17, 2018, 08:31:15 pm »

$45 postage !

Well that has put me off getting one for sure. In the UK we pay 20% VAT on the items cost plus the postage cost. That appears a crazy cost for such a small and light PCB. The $70 asking price for what you get isn't wonderful either. Compared to China sourced kits and populated PCB's it is darned expensive.

Fraser

Fraser · « **Reply #9 on:** February 17, 2018, 08:35:43 pm »

For anyone needing a faulty FLIR One G2 (160 x 120) to either repair or harvest the Lepton from, I have five at the moment that I have lost interest in repairing. My location is the UK but these are quite cheap to ship anywhere in the world. I am asking £70 plus shipping (what I paid for them) per complete Flir One G2 in the box. I have Android and iOS versions.

Contact me via PM if interested. Certainly cheaper than buying a new Lepton 3 and there is the chance of repairing the F1G2 if you feel so inclined !

Fraser

jean-paul · « **Reply #10 on:** February 17, 2018, 09:56:33 pm »

mahony,

I saw the first one on eBay but I wasn't sure it's an G2.

Yes postage fees are so expensive on Groupgets... but it's the only way to get this second generation. I think I'll buy one anyway because it seems one of the best way to connect a Lepton to a laptop.

I don't know if FLIR plans to release a 4th generation anytime soon of the lepton!

Fraser, that's cool! thanks

Fraser · « **Reply #11 on:** February 17, 2018, 10:16:22 pm »

The Lepton 3 has reached its resolution limit with the current lens structure (Silicon diffraction type) so any new, higher resolution, version would need a lot of redesign work around the lens area. Such is very likely to increase cost.

Fraser

stainlessjimmy · « **Reply #12 on:** February 17, 2018, 11:00:12 pm »

May be Tinkerforge Thermal Bricklet may be alternative for you, it is 249 Euro + you need master brick also (29 Euro) :
https://www.tinkerforge.com/en/shop/thermal-imaging-bricklet.html
This is radiometric Lepton version, i use it on Windows as well standalone with tinkerforge RED brick:

Spirit532 · « **Reply #13 on:** February 17, 2018, 11:04:43 pm »

80x60 pixels is way too low for home inspection.
160x120 is pushing it, and I would recommend 320x240 if possible(but that is out of his budget).

Fraser · « **Reply #14 on:** February 18, 2018, 02:31:57 am »

Jean-Paul,

I have sent you a PM.

As has been stated, a professional thermal audit of a building usually requires 160 x 120 pixels or more for efficiency. Though, as I have detailed in my message to you, people need to also consider the field of view that a camera is providing Vs the number of pixels, as a wide FOV can be detrimental to detail. Lower resolution thermal cameras address this with narrower field of view lenses. With a lower FOV the same detail as a higher resolution camera may be achieved, but at the cost of the 'broader view' In some cases however this is of no great importance as the camera is 'scanned' over the building. The Lepton equipped F1G2 lens is sadly quite a wide FOV at over 40 degrees and the latest F1G3 is 50 Degrees horizontal. Resolution on its own can be misleading. The thermal scene detail capture is a combination of microbolometer resolution, lens quality and lens FOV. Sadly the silicon diffraction lens in the Lepton is nothing to get excited about, which does not help matters.

As has been stated, for professional building thermography a decent 320 x 240 pixel thermal camera is recommended. It is really down to what you truly need for the tasks you have in mind. When it comes to commercial thermography the budget is sadly set by the task requirements and not just what can be afforded. You, however, may not have such a demanding requirement. It is easy to spend a lot of money on a thermal imaging camera, but sadly it is hard to spend just a little ! There is limited choice at the lower price end of the market as the parts within thermal imaging cameras can still be expensive to the OEM. This is why the Lepton is somewhat revolutionary..... It is a cost reduced thermal imaging core that uses a lens that would normally be considered useless for Longwave imaging as it is Silicon. Yet FLIR produced a usable, if not wonderful, silicon lens that massively reduced the cores production cost. The much smaller microbolometer die that uses 12um pixels also helped reduce cost, but at a price. That price was image noise. FLIR use their knowledge of thermal image processing to reduce the noise to acceptable levels.

I do not think FLIR designed the Lepton to be a core used in professional thermography though ! It can certainly be pressed into service as a reasonable thermal imaging core, but just do not expect too much from it.

Hope this helps

Fraser

mahony · « **Reply #15 on:** February 18, 2018, 09:21:06 am »

Quote from: Fraser on February 18, 2018, 02:31:57 am

... The much smaller microbolometer die that uses 12um pixels also helped reduce cost, but at a price. That price was image noise. FLIR use their knowledge of thermal image processing to reduce the noise to acceptable levels. ...

I agree that there is some really disturbing noise in the Lepton images, notably quite high shot noise that I don't see to any extend in the Thermal Expert and which is significantly decreasing NETD (>100mK from what I have seen in the raw images). I am not sure if that noise isn't added intentionally? The 12µ technology is also used in the new Boson cores and in there it is capable of <=40mK (from datasheets).

By the way: is anyone up for a group buy of the PureThermal?

jean-paul · « **Reply #16 on:** February 18, 2018, 11:30:49 am »

@stainlessjimmy it's the Lepton 2.5 which only has 80x60 pixel

I don't intend to do professional thermal imaging. I'd like to do a mosaic of photos (with a fixed scale) and then assemble them to got a higher resolution image.

I also looked for a used FLIR Tau core but it's impossible to find. The Thermal Expert seems good but a price over budget.

Vipitis · « **Reply #17 on:** February 18, 2018, 12:01:42 pm »

It's really hard to do panorama stiching with such a wide fov of the Lepton. And you get really disturbed results. And moving the camera... Is difficult on a building scale

mahony · « **Reply #18 on:** February 18, 2018, 02:16:47 pm »

You can however 'attach' different lenses to the Lepton.
Attached are some shot of a Lepton3 with the ThermalExpert 13mm f/1.0 lens and the ThermalExpert Q1+ with a FLIR 36mm f/1.2 lens. The FOV is almost the same, the level of detail and especially the noise level are a totally different story. The Lepton images are 2x upscaled w/o any interpolation, sharpening or whatever - just raw images from both camera at roughly the same time. Both cameras did run for ~5 minutes are where just NUCed.

I would suggest saving some money and go for the TE-Q1 - I imported mine (the Plus version) directly for ~800€ all included - there are also some on eBay in Germany/Europe currently used ~750€, as well as new ~900€ (and one from joe-c actually ;-)). If you do not need fast frame rate I think this is the best value for the money at the moment.

Vipitis · « **Reply #19 on:** February 18, 2018, 02:39:42 pm »

That's very interesting. The clarity makes a huge difference. I am dreaming about narrowing the Lepton fov to increase resolution. And get better results at stiching panorama shots with a panning motion.

I asked TPL about their unit for the T12 imager and got quoted 300$.

My best option is probably to buy 2 ZnSe or Ge lens elements and 3D print the housing and connection for it. But I am indecisive and have a hard time spending money.

jean-paul · « **Reply #20 on:** February 18, 2018, 03:13:43 pm »

Wow nice!

This thermal expert seems one of the best quality/price ratio out here. If I can find a used Therm App or Thermal Expert it would be great!
What about the Seek Thermal Pro?

Fraser · « **Reply #21 on:** February 18, 2018, 03:50:19 pm »

For others info, I tested my SATIR MinIR80 thermal camera for building survey work. Result...... simply not suitable. The resolution is just too low, even with a 20 degree FOV lens. I have offered the OP a brand new, boxed, Irisys IRI4035 at what I think is a decent price, and a fraction of the list price, but that will be for him to decide.

https://www.iristem.gr/999171C9.en.aspx

As has been previously stated, 160 x 120 pixels is the minimum, preferably fitted with a 20 or 24 degree FOV lens if decent detail is needed.

I am dropping out of this thread because I do not have anything to offer the OP in terms of a camera with the required resolution and imaging performance, within his price range. It is very challenging to match up a decent camera with a potential owner at this 'bargain basement' end of the market.

All the best

Fraser

Fraser · « **Reply #22 on:** February 18, 2018, 03:56:09 pm »

I have been asked by the OP whether a Lepton3 is adequate for the intended task.

I think the easiest way for me to deal with this is to take some pictures of houses with my FLIR One G2 and upload them here.
I will have to go charge it up first though. Nothing demonstrates camera capability like a real world picture eh

Fraser

Fraser · « **Reply #23 on:** February 18, 2018, 04:56:33 pm »

OK, test completed.

It is my opinion that the Lepton3 is challenged when it comes to providing detail of building exteriors and small temperature differences. The combination of a wide angle lens and 160 x 120 pixel resolution conspire to produce images that are relatively low on detail. In contrast, images of my cat come up OK. The reason is simple. The F1G2 was intended to image things quite close, like pet cats and friends ! these have high temperature differences that provide far more contrast in the images and tend to cover up the fact that detail is still low.

The software used for the test was that from Georg as it provides the full 160 x 120 pixels image and enables removing of the MSX function. I did this because the OP was considering using a Lepton and interface board, rather than an F1G2 equipped with visible light camera and MSX. My pictures were in the auto exposure mode and not tweaked fro best image. They are deliberately as 'RAW' as I could make them as that is what awaits stand alone use of the Lepton core.

The Lepton is suited to certain tasks, especially those with high thermal contrast. It is less suited to others as can be seen in my pictures. i deliberately include some pictures of our cat and a Hi-Fi unit adjacent to a radiator and a heating system pipe buried in the stud wall.

I honestly cannot recommend a Lepton for any serious kind of building thermography. It is very much 'horses for courses', simple as that.

Fraser

Fraser · « **Reply #24 on:** February 18, 2018, 06:07:48 pm »

Some sample pictures taken with the Irisys IRI4035 160 x 120 pixel camera.

These are as 'raw' as I could make them. No careful setting up or processing of the picture. Just nice and RAW

Te camera was started and set to auto, nothing else was done before taking pictures. Nicer looking pictures are possible at the expense of Delta V detail.

Note teh IRISYS camera software does a great job of smoothing and interpolating the image up to 640 x 480 but such would be an unfair comparison against the Lepton images.

160 x 120 pixels is enough, if inside the right camera

Oooops ! Pictures need to be changed from BMP so I will do that and upload ASAP.

Fraser

Fraser · « **Reply #25 on:** February 18, 2018, 06:18:16 pm »

Irisys IRI 4035 pictures - no post processing and in the RAW.

Fraser

jean-paul · « **Reply #26 on:** February 18, 2018, 08:21:33 pm »

Thanks for these image Fraser! I thought the Lepton3 would have been better

The Irisys IRI 403 outputs better images! For it's a different price.

I think I need to save money and spend at least 500€ to have something decent. I'll look on eBay if I can get a core or a Flir E4 for this price tag.

So to sum up this thread:
- $300 is not enough for building thermography, a budget of at least $600 is needed
- $800-$1000: we can get a Thermal Expert or a Therm-App or a decent used FLIR
- For $300 what would the best? A used LWIR core? or a Lepton3 + PureThermal2?

Thank you

mahony · « **Reply #27 on:** February 18, 2018, 08:31:59 pm »

Just to bring another option on the table, that might be quite close to your budget is the Seek Compact Pro currently on eBay for ~500€:
https://www.ebay.de/itm/Thermal-Imager-Seek-Compact-Pro-FF-Android-320x240p-Wärmebildkamera-Compactpro/282203560246?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

I would actually like to try one of those but maybe someone from the forum can help you with actual building images for this dongle. 320x240 with 32° FOV should be quite o.k. for the task.

Spirit532 · « **Reply #28 on:** February 18, 2018, 08:38:05 pm »

For $300 and building inspection I recommend buying a used core. There are a few options on eBay just a hair over $300 for a 320x240 core with composite output.
A budget of ~$600-750 expands your options vastly.

Quote from: mahony on February 18, 2018, 08:31:59 pm

I would actually like to try one of those but maybe someone from the forum can help you with actual building images for this dongle. 320x240 with 32° FOV should be quite o.k. for the task.

I have a Compact Pro - it works, definitely. The standard apps are quite meh, but JoeC's software allows you to push it quite far.

jean-paul · « **Reply #29 on:** February 18, 2018, 08:43:53 pm »

The Compact Pro is much better than the non-Pro? I haven't read good review on the non-Pro.

Do you have a link of a used core around 300€ please? I don't find one on ebay.

Thank you

Spirit532 · « **Reply #30 on:** February 18, 2018, 09:40:01 pm »

The Pro is 320x240 and has a much better sensitivity and noise characteristic than the non-Pro.
As for links - just keep searching, they pop up once in a while. You may have to negotiate shipping with the US sellers and confirm with them that you're in an STA-exempt country(and therefore do not require export licensing).

Bill W · « **Reply #31 on:** February 19, 2018, 06:18:06 pm »

Good to see some examples of a FLIR with a decent lens.
This is my thoughts too, the Flir-One modules are simply not even focused.
Experiments ongoing (slowly) putting a Flir-One behind decent germanium.

As for second hand cores, there's the GBP150 Raytheon 2000AS's from the thread
https://www.eevblog.com/forum/thermal-imaging/raytheon-2000as-core-teardown-and-back-up-again/
http://www.fire-tics.co.uk/project1/index.htm

regards
Bill
(fire-tics is my site and goods, but better someone here than eBay or even the wider forum !)

Revan · « **Reply #32 on:** February 21, 2018, 07:18:33 pm »

I have some questions about the Flir Lepton 3.

1. Is it possible to see smoke leaving from normal house chimneys or charcoal grills at a distance of 40-60 m and < 80 m?
Especially smoke that is only visible in IR?

2. The PureThermal 2 has an onboard STM32F412 ARM microprocessor running at approximately 100 MHz. Isn't a breakout board for the Lepton 3 and a Raspberry Pi 3 a much better choice? The Raspberry Pi 3 has a much faster processor.

3. If 1. requires some sort of lens optics what kind of low price optics would work and were can they be bought at low prices.

Spirit532 · « **Reply #33 on:** February 21, 2018, 08:16:55 pm »

Quote from: Revan on February 21, 2018, 07:18:33 pm

1. Is it possible to see smoke leaving from normal house chimneys or charcoal grills at a distance of 40-60 m and < 80 m?
Especially smoke that is only visible in IR?

No. This is exactly why LWIR cameras are used by firefighters - to see through smoke. At 60-80m you'll be lucky if the Lepton can differentiate between a working grill and a burning car.

Quote from: Revan on February 21, 2018, 07:18:33 pm

2. The PureThermal 2 has an onboard STM32F412 ARM microprocessor running at approximately 100 MHz. Isn't a breakout board for the Lepton 3 and a Raspberry Pi 3 a much better choice? The Raspberry Pi 3 has a much faster processor.

It's only for reading the sensor out and serving a UVC device to a host computer. Not much processing required. It's barely enough to attach a display to it(and with the new firmware features, I doubt even that is possible).

Quote from: Revan on February 21, 2018, 07:18:33 pm

3. If 1. requires some sort of lens optics what kind of low price optics would work and were can they be bought at low prices.

LWIR optics are just expensive, period. You're never going to find anything new for a low price.

Best you can do is probably hacking together your own lens using CVD ZnSe or GaAs elements for CO2 lasers, but that's on the fringe of what's possible, and still in the hundreds of dollars range.

Revan · « **Reply #34 on:** February 22, 2018, 11:31:11 am »

Thanks a lot for your answers.

1. Why is it possible to see the heat emission on these pictures with an IR camera?
http://www.flir.eu/fire/blog/details/?ID=73308
http://www.alamy.com/stock-photo-infrared-thermography-image-showing-the-heat-emission-at-the-chimney-78791517.html

Something like this is all i want to be able to see with such an IR camera, a difference between the cold sky and the heat emission of the none visible smoke.

EDIT:
Here are two more pictures:
http://baltimorefishbowl.com/stories/greenlaurel-surprisingly-senate-blocks-trumps-attempt-to-cancel-methane-rules/
https://www.alternet.org/environment/hold-your-breath-nearly-200-infrared-videos-expose-methane-pollution-all-across-united

Fraser · « **Reply #35 on:** February 22, 2018, 12:41:04 pm »

Revan,

I think this is a terminology issue. You stated you wanted to see "smoke" leaving a chimney. As has been stated, Longwave thermal cameras are useful for seeing through "smoke". What you are actually wanting to image is the thermal energy leaving a chimney and this can be imaged with a thermal camera. It could be argued that there is always heat accompanying smoke coming out of a chimney but I think your specific request to see "smoke" caused some confusion.

Whether a Lepton core can image such thermal energy is actually a little hard to answer. The Lepton3 cores come with a wide angle lens so the minimum resolvable target at a stated distance applies. Heat emissions out of a chimney should be DETECTABLE at around 50m but I would not want to say they would be seen at 100m. I have no suitable chimneys around me to check.

One thing to be aware of, the sky is very cold to a thermal imaging camera. This can force quite wide thermal imaging spans in a fully automatic camera. Such wide spans can be detrimental to imaging some temperature differentials. It is better to manually select the temperature span of, for example, 10C and then set the centre temperature to that of the emission coming out of the chimney. You may need to set a wider span in order to gain the best image of the emissions.

This sort of imaging is normally the realm of industrial thermal cameras and a resolution of 320 x 240 pixels with 24 Degree, or less, FOV lens is preferred. The Lepton series of cores are at the bargain basement end of the market. You will not achieve impressive imaging with such a core, but if "detection" is your intention, it may work well enough for you if a Lepton3 is used.

You have not detailed why you wish to image the thermal emissions out of chimneys etc. Is it a project to study the thermal air behaviour, vorticies etc ? If so, that is beyond the capabilities of the Lepton3 and its wide angle lens. To study heated air interaction with the surrounding atmosphere and vorticies etc, I would use a high performance 320 x 240 pixel thermal camera fitted with a telephoto lens. The telephoto lens would provide the confinement of view needed to extract decent thermal scene detail with only 320 x 240 pixels. The telephoto lens FOV would be chosen to suit the distance from the target and required detail in the image. I would expect to use a 7 Degree FOV lens to look at a chimney on a house. That is a sixth of the FOV provided by the Lepton3.

On the 'cheap' telephoto lens front, there are none

Thermal camera lenses are made from materials that are inherently expensive. Germanium, IR Chalcogenide Glass and ZnS being commonly used. Telephoto supplimentary afocal lenses do come up for sale on eBay occasionally but they are by no means "cheap". New supplimentary lenses from FLIR and FLUKE cost thousands of US Dollars.

If you have a project that needs to image the thermal emissions from chimneys etc, it might be better to hire a suitable professional thermal camera and telephoto lens. It will be cheaper than buying equal performance, even used.

Fraser

Fraser · « **Reply #36 on:** February 22, 2018, 01:01:56 pm »

Further to my last, I see you have included references to imaging Methane gas emissions using thermal imaging techniques. These emissions are not "smoke" But some are IR reactive and can emit thermal energy. You would need to study gas imaging with thermal cameras to determine what wavelengths are involved and whether one of the specialist gas imaging thermal cameras is required.

Fraser

Spirit532 · « **Reply #37 on:** February 22, 2018, 01:30:59 pm »

I'd also like to add that some of the linked pictures are either fake(like the alamy one), or use midwave infrared(MWIR) cameras with specific filters for OGI(optical gas imaging), in the 3.5-6um range, with a few notches for absorption lines of various carbobyhdrates like methane.
The only exception is the first FLIR one, which is seeing a huge fire and only a few wisps of extremely thick smoke.

Revan · « **Reply #38 on:** February 22, 2018, 02:30:22 pm »

Fraser & Spirit532,

thanks a lot for your answer this will help me a lot.

Quote from: Fraser on February 22, 2018, 12:41:04 pm

You will not achieve impressive imaging with such a core, but if "detection" is your intention, it may work well enough for you if a Lepton3 is used.

Yes, detection is all i need.

Quote

You have not detailed why you wish to image the thermal emissions out of chimneys etc. Is it a project to study the thermal air behaviour, vorticies etc ?

No, all i want to do is just detect if and which chimney is active and in summertime which neighbor has an active charcoal grill running.

Some might ask, why not just use your eyes?
Well, this isn't as simple as it sounds. The main problem is the smoke is not always visible in the visible electromagnetic spectrum.
It depends on light conditions, the burning material and its humidity and for charcoal grills vegetation is often obstructing direct visual contact.

That's why i was thinking about detecting these things by the thermal energy of the smoke or the surrounding of the fireplace.
All i need to detect is if there is something active and in which direction/location.

Quote

I would expect to use a 7 Degree FOV lens to look at a chimney on a house. That is a sixth of the FOV provided by the Lepton3.

On the 'cheap' telephoto lens front, there are none Thermal camera lenses are made from materials that are inherently expensive. Germanium, IR Chalcogenide Glass and ZnS being commonly used. Telephoto supplimentary afocal lenses do come up for sale on eBay occasionally but they are by no means "cheap". New supplimentary lenses from FLIR and FLUKE cost thousands of US Dollars.

Could i also use a Newtonian telescope with a mirror made of blank metal instead of a lens and attach the Lepton 3 to it?
As far as i know blank metal can reflect IR radiation quite good and the shaped metal mirror might magnify the image too.
Such a metal mirror would be also much cheaper.

This principle work's at least in the visible light with normal Newtonian telescopes and mirrors.

Vipitis · « **Reply #39 on:** February 22, 2018, 03:03:50 pm »

So, I looked around my neighborhood. I saw a few chimneys steaming. It's visible and also visible in the shadow. I pulled my phone phone, which features a 80x60 Lepton2.

I took images of steaming chimneys about 30meters away. And then our own chimney, from just 2.5m away. I believe all Houses in this neighborhood use gas based heating.

I attach some images, taking in FLIRs MSX Mode and in the Thermal Camera + superresolution mode, with limited minium temperature to reduce the dynamic range of the cold sky.

I think it's save to say that you can see nothing. Might be the emissions that get burned here, but you get the wide angle idea. The Lepton3 has higher resolution, but that won't make a huge difference.

Newtonian telescope with mirrors should in theory work. I think Ultrapurple has pulled off some moon shots with a ThermApp and a newt; most telescope mirrors have glass with a coating that reflects quite okay in the LWIR spectrum. I don't have the scope to try it. But you could theoretically make a mylar based mirror with good reflection.

mahony · « **Reply #40 on:** February 22, 2018, 08:21:22 pm »

As long as the gas or particles or whatever exits the chimney of interest is warm enough your will be able to see it on a thermal camera.
I don't see why the alamy picture should be fake. Especially warm/hot water vapor will be happily recognized by a LWIR camera. Clouds are nothing more than water vapor at roughly ambient air temperature and will give you significant thermal contrast with respect to surrounding blue sky.

Attached is a picture of Christmas decoration with some candles, you can actually see the hot/warm gas quite far up. Note, that the color scale is logarithmic, otherwise to only visible parts would be the very center of the flames.

With the TE-Q1 I saw smoke/hot air off chimneys quite often, but have no image at hand...
If interested in I can try to take some with me 13mm Lepton setup as over the next couple days.

mahony · « **Reply #41 on:** February 22, 2018, 08:38:58 pm »

I couldn't resist and pulled out the Lepton3 with the 13mm TE-lens and looked around a bit. The 'smoking' chimney is on the next house, according to google ~60m away.
On the other 2 images you can see nothing but the 'hot' stove pipes + I guess the gas is so cold that there is simply not enough contrast to the surrounding roof tops...

All images are from raw digital values with linear scale from min to max pixel value.

Revan · « **Reply #42 on:** February 23, 2018, 10:26:22 am »

These are great pictures. Thank you very much to both of you for sharing.

@mahony
If i get this right, you put the lense of the TE–Q1 on top of the Lepton 3, is this correct?

Bill W · « **Reply #43 on:** February 23, 2018, 01:42:48 pm »

Quote from: Revan on February 21, 2018, 07:18:33 pm

3. If 1. requires some sort of lens optics what kind of low price optics would work and were can they be bought at low prices.

From the teardowns on here you can see the lens is removable. We also know the sensor is small and also small pitch.
This means tow things, one good and one bad.
On the good side you will not need a 200mm lens - 'not too long' focal length will still be a fairly narrow field of view and likely narrow enough for handheld use.
On the bad side many older lenses will not be resolving well at 12µm pixel pitch, a lot were designed around 50µm pixels.

That said I have this as an experiment in the 'to do' pile, putting a open F1 body behind all the lenses I have. If any work Ok then I will say so.

What would you think is low cost ?
GBP/EUR 1 is not happening
GBP / EUR 50-100 opens up the kind second hand / recovered lenses from equipment mentioned above.

There used to be a rule of thumb that once the lens cost more than the camera, you had the wrong camera.....

regards
Bill

regards
Bill

mahony · « **Reply #44 on:** February 23, 2018, 04:41:22 pm »

Yes, I took the lens from the TE-Q1+ (the 13mm version) as I am mostly using the TE with a 36mm FLIR lens (from a FLIR A20 I think).
I just removed the lens a described on one of the tear down videos. You can also put it back on later - the big benefit is you can then fine adjust the focus. Both Leptons I pulled from F1G2s where a bit too close focused / not at infinity - probably for indoor use.

On the Lepton you get a FOV of ~8.5°x6.4° (12µm/13mm -> 0.93mrad iFOV @160x120px results in ~148x110mrad). The 36mm on the TE-Q1 result in 0.47mrad iFOV and 10.4°x7.8° full FOV which is quite nice for longer range playing. Detection of people/animal is possible up to ~800m, probably even more. I was not sure about the sharpness of this 'old' lens on a 17µm Imager but turns out it has totally sufficient sharpness. At some point I am going to test is on the Lepton too because I want to see if it might be an option for a Boson core at some point in the future :-D

I have attached some images of both conversions. The Lepton setup is still very 'experimental' whereas the TE-FLIR combo is finalized after 2 iterations of prototypes.

Vipitis · « **Reply #45 on:** February 23, 2018, 05:20:08 pm »

You should take a panorama tripod head and stich multiple images of the Lepton with the lens to see if you can get good results for a high resolution stiched image. You will need to lock palette, gain and stretching to get consistent results. Also consider the FCC shutter cooldown.

mahony · « **Reply #46 on:** February 25, 2018, 11:20:57 am »

Yes, I am planning on something like this. I already have a self-made Pan-Tilt head that would need some software mods to do an automated pattern for panorama stitching. BUT if I do this I probably just use the TE-Q1 ;-) and before I have to check-out Photoshops capabilities in stitching 16bit monochrom .tif files.
It might be interesting to see the differences on a final high-res image between the Lepton and the TE.

jean-paul · « **Reply #47 on:** March 04, 2018, 12:40:11 pm »

Hello,

To conclude this thread, the best it an used camera!

Here is an example of a panorama with 7 images 160x120

Fraser · « **Reply #48 on:** March 04, 2018, 12:47:32 pm »

Jean-Paul,

Nice Panorama

I am so pleased that the camera went to a good home where it will get plenty of use.

Warning - You could catch the 'thermal bug' and start your own collection of cameras

Fraser

jean-paul · « **Reply #49 on:** March 04, 2018, 01:13:01 pm »

Hi Fraser,

Yes I need to be careful! If I win at the lottery I'll know what to buy!

Vipitis · « **Reply #50 on:** May 25, 2018, 08:51:51 am »

This thread is ancient, but I had the feeling we had the discussion a few times. I found an open source hardware&software project for a 160x120 Lepton based imager that is supposed to cost 400€ https://github.com/maxritter/DIY-Thermocam

Maybe something for people who don't want to spent long time developing firmware.

elec2012 · « **Reply #51 on:** September 04, 2018, 01:35:51 pm »

Hi does anybody know this:

https://www.photonics.com/Products/IR_Thermopile_Array_with_80x64_Pixel/pr59875

Fraser · « **Reply #52 on:** September 04, 2018, 01:48:57 pm »

The sensor was at the heart of a Kickstarter campaign thermal camera that, as far as I know, never shipped.

https://www.kickstarter.com/projects/ebeall/hemavision-smart-thermal-imaging-with-computer-vis

Technology has advanced moved quickly in the world of Thermal Cameras and I think the Hemavision camera was a victim of that. Other competing products with better resolution came to market around the same time. It was a very good effort on the part of Mr Beall though and he did have working prototypes.

http://www.hemaimaging.com/

The sensor is a thermopile, so similar technology to that used in IR thermometers and some low resolution IriSys thermal people counters and cameras. Microbolometers effectively "own" the consumer thermal camera market these days.

Fraser

Fraser · « **Reply #53 on:** September 04, 2018, 01:58:46 pm »

I can confirm that the Hemavision camera product was cancelled in 2016 due to the loss of two key components and redevelopment costs.

http://www.hemaimaging.com/status/

I think Mr Beall was/is a member of this forum though. If you want an expert view of these thermopile sensors, he may be your man

Fraser

elec2012 · « **Reply #54 on:** September 04, 2018, 06:52:23 pm »

Okay.
But I will try the AppSet for EUR281

http://www.heimannsensor.com/products_imaging.php
80x64 px

thx

Ben321 · « **Reply #55 on:** September 04, 2018, 07:21:37 pm »

Quote from: Spirit532 on February 16, 2018, 06:16:55 pm

The Lepton3 breakout + Raspberry Pi(a clone works too) and a display could be a good option if you're willing to tinker to get it working.

What do you need the camera for? There are a few good options on the used market too, but they might not be fit for your your needs(analog video out, etc).

Who uses a Pi? It's useless if you want to stream into your PC. You can stream it into the Pi, but then you need to capture the image and transfer it with an SD card or something. Now if there was a USB breakout board for the lepton, and it allowed you to plug it directly into your PC, now THAT would be a good thing.

mahony · « **Reply #56 on:** September 04, 2018, 08:05:40 pm »

Actually there is a board streaming directly to USB if wanted:
https://groupgets.com/manufacturers/getlab/products/purethermal-2-flir-lepton-smart-i-o-module#discussion

It is based on some STM32 chip an software is on GitHub to be modified to your needs.

The other option might be a Teensy 3.6 based approach (as does the DIY Thermal cam) - you could either stream to the USB port or attach a small display as you like. This is the cheapest option for me: 30€ Teensy board + 80€ for a Lepton from a dead FLIR ONE + 10€ for a 1.8" TFT ... just need to find the time to test this. ;-)

And who says you can stream to a PC from a PI - I do exactly this on a PI3 via Ethernet or WLAN. WLAN is not the most stable solution but Ethernet works like a charm. Also the PI Zero works but is limited to the WLAN connection which might not be the best for a continous stream. Bluetooth may work too but I never played with it.


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