Author Topic: Best thermal camera for $300 (Read 12993 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


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Author Topic: Best thermal camera for $300 (Read 12993 times)

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