Building a DIY thermographic setup - cheaper alternative to thermal cameras?

Right, so thermal cameras are brilliant for paranormal investigation but they're absolutely extortionate. The decent ones are £2,000-£5,000 minimum. I've been researching whether you can build a DIY setup using thermal smartphone attachments or even thermal sensor arrays hooked up to a Raspberry Pi.

Has anyone tried this? I found a few YouTube channels where blokes have rigged up thermal sensor arrays for about £300-£400 total, though the setup is quite fiddly and requires basic electronics knowledge. The images aren't quite as clean as a proper thermal camera, but for detecting temperature anomalies, they seem to work decently.

Before I start ordering parts, I wanted to check: has anyone in the community built something similar? What was your experience? How accurate is it compared to consumer-grade kit? And more can you actually catch evidence with a dodgy DIY setup or is it a waste of time and components?

I had a go at this about two years ago using a Flir Lepton sensor and it was... okay. Cheaper yes, but the spatial resolution isn't great and the software is clunky. You get a rough idea of temperature distribution but nothing as detailed as a proper thermal camera. That said, for the price, it's worth a punt if you've got soldering skills.

Honestly, save up for a second-hand proper thermal camera. I bought a Flir E8 on eBay for £800 and it's infinitely better than any DIY setup. You can get older models cheap enough now. The DIY stuff is fun if you like tinkering but practically speaking, you want genuine thermal imaging for serious investigation.

The images aren't quite as clean as a proper thermal camera, but for detecting temperature anomalies, they seem to work decently.

That's the key question though - does 'working decently' actually catch evidence or does it just let you think you've caught evidence? Paranormal investigation is already plagued with confirmation bias. Adding fuzzy DIY thermal data to that seems risky. Better to have one solid piece of equipment than multiple dodgy ones.

I'd say build the DIY setup if you enjoy the project itself and don't mind it being imperfect. Good learning experience and you'll understand thermal imaging better. But don't fool yourself thinking it's equivalent to proper kit. Use it as a secondary device, not your primary thermal source.

There's a middle ground - smartphone thermal attachments are about £200-£400 and they're pretty decent quality. Not professional grade, but miles better than DIY and still way cheaper than a proper thermal camera. I've used the Seek Thermal and it's decent for paranormal work. Something to consider before you start breadboarding circuits.