HY-18 - neat little matchbox TI

[Ultrapurple]

Has anyone any experience of the HY-18 miniature thermal camera? Resolution is stated as 60x60 so nothing to write home about but it's a nice little form-factor. The image below is a mildly modified screendump from eBay but there are many sellers. Price seems to be about US$100 or less.

Looks like an interesting toy, if nothing else, and the small screen means the low resolution is less immediately obvious.

[Fraser]

True resolution is 32 x 24 as it uses the MLX 90640 sensor. They are using interpolation to claim 60 x 60. Bit naughty 

There are other cameras based on what looks to be the same, or very similar hardware.

https://www.ebay.co.uk/itm/MLX90640-thermal-imaging-camera-Thermodetector-2-4-32x24/254350762395?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20160908105057%26meid%3Daad9885519b5452b8838e2d82856a954%26pid%3D100675%26rk%3D2%26rkt%3D15%26sd%3D293251395126%26itm%3D254350762395%26pmt%3D0%26noa%3D1%26pg%3D2380057&_trksid=p2380057.c100675.m4236&_trkparms=pageci%3A76ab7838-f3e5-11e9-8b9d-74dbd180329e%7Cparentrq%3Aeda79b4916d0a4b7fcced316ffe9f477%7Ciid%3A1

https://www.ebay.com/itm/MLX90640-32x24-IR-Camera-Infrared-Thermal-Imager-Thermodetector-Infrared-Camera/283538154210?hash=item420430e2e2%3Ag%3A5q4AAOSwYjRdjCxS&LH_ItemCondition=3

MLX90640 thermal imaging camera Thermodetector 2.4” 32x24
product description
1.→Using MLX90640BAB infrared thermal imaging sensor
2.→ Resolution: 24×32.→ Temperature measurement range: -40°C~300°C
4. Measurement accuracy: +/- 2 ° C (center area, 0 ~ 100 ° C).
5.→Working temperature: 0°C~50°C
6.→ Refresh rate: 8HZ
7.→No calibration required
8.→Field of view: 35°×55°
9.→Emission rate 0.1~0.95 adjustable 10. Display center point, highest and lowest temperature.
Product packaging: MLX90640 thermal imager, no power supply, no charging cable, no rechargeable battery

Fraser

[bap2703]

Also note that these are slow and poorly sensitive.
At 1 Hz netd is already at best 100mK.
I can't imagine what you get at 8 Hz.

[Ultrapurple]

True, performance is a little limited in terms of the more-expensive devices we know and love. But imagine what would have happened if you'd rolled up with one of these at Agema's door in 1990...

[Fraser]

You would have been tied to a stake and burnt alive as a Witch or Warlock 

[Fraser]

What I like about these units coming out of China is that they are embracing the new affordable IR sensors and using them to produce thermal images. These low resolution sensors were never really intended to be practical thermal imaging cameras in the consumer market. They are really a ‘high resolution’ PIR sensors for applications that benefit from gaining a little more information about the target. In that role, they are both well suited and very advanced compared to your bog standard 4 pixel PIR sensors 

The fact that these units are eminently affordable makes for a good educational platform to teach people about thermal imaging and thermography, without breaking the bank. To me, that is a great step forward as it engages people and children with the potential uses of thermal imaging technology. That can only be good for the Industry and also new product ideas and development.

As a side note, I was offered lots of Lepton 2 80 x 60 pixel units last week ....  they are brand new and only £30 each ..... I was tempted as they might be fun to experiment with. I have so far resisted the offer though 

Fraser

[Ultrapurple]

You would have been tied to a stake and burnt alive as a Witch or Warlock 

Hopefully as a Warlock...

You don't think they'd believe I'd bought it on eBay? (No, wait, eBay hadn't been invented yet...) I'd have to say I'd stolen it from DARPA.

I did recently see that DARPA has three sample uncooled LWIR cameras on a 5µm pitch, which look rather interesting even if they are a long way from being available from your local DIY shop. 5µm pixels would roughly mean 1920 x 1440 resolution in the same sized package as today's near-commodity 640x480 17µm devices. Given that (very broadly speaking) sensor cost is proportional to surface area, that bodes well for affordable full-HD-class cameras Real Soon Now™- I do like the idea of a Therm-App HD...

[Fraser]

Optics, optics, optics 

Sadly the resolution of the sensor and pitch has an effect on the quality of the optics required. Current thermal cameras ‘get away’ with relatively simple low resolution optics. Just think about the junk lenses that used to be used in VGA web cams to see what you can get away with at low resolutions  Even the better Industrial thermal cameras contain an optical block that would make Digital camera lens manufacturers laugh. They are basic but get the job done.

Once you step up to ‘serious’ resolutions on smaller pixel pitches, you start to notice the limitations of the current ‘simple’ optics and their less than perfect optical properties. To improve upon those optics will be a development and investment commitment from the thermal camera and lens manufacturing industries. It is true the Chalcogenide IR glass that can be moulded has reduced lens element costs but I am unsure whether a moulded Chalcogenide IR glass lens will be good enough for high resolution work as its crystal structure is, to be frank, a mess ! It gets away with use as a thermal camera lens at the moment because of the low resolution involved. High quality optics still need the best Diamond cut Germanium lens elements. Hence why high resolution military lenses are Germanium and horrifically expensive.

Fraser

[ArsenioDev]

I've been looking at futzing with the Lynred FPAs, they're MUCH better quality and honestly not much more than that system in low QTY. Already am in contact with them and pricing out  costs to get my hands on some of their sensors. Downside is the NDA locking and headaches involved there, also ITAR but eh, comes with the territory.

[Bill W]

As for optics, remember that current mobile phones have lenses that will not out-resolve the sensor.  The use the oversampling (say 5x5 pixels for any resolveable blob) to perform a lot of image processing magic which it would be disrespectful to call simply sharpening.

Thermally we are used to the opposite, where it is a struggle (financially at least) to have lenses that outperform the sensor.

Bill