Read the detector resolution, not the image resolution. Listings routinely quote both, and the larger one is produced by upscaling.
What each size resolves
- 80 × 60 (4,800 points): large, high-contrast features. A missing insulation batt, a cold bridge, a blocked radiator, a hot connection in an open box.
- 160 × 120 (19,200 points): individual pipes in a run, individual components in a distribution board.
- 256 × 192 (49,152 points): detail at distance, and images that survive being cropped into a report.
How to find the real figure
It is the smaller number, usually qualified with “thermal”, “IR”, or the word “from”. One camera we compare states 1440 × 1080 image and 80 × 60 thermal in the same sentence; another states 320 × 240 derived from 160 × 120.
The other figures that matter
Thermal sensitivity in millikelvin decides whether a faint difference appears at all. Emissivity adjustment matters for the same reason it does on an infrared thermometer — a shiny surface reports a temperature that is not its own.
What gets asked here
Does a thermal camera see through walls?
No. It sees surface temperature. A stud appearing through plasterboard is a surface temperature difference caused by what is behind it — useful, and not the same thing.
Is a phone-attached camera good enough?
For building fabric, yes. It depends on a compatible phone, which is the real limitation rather than the optics.
Last reviewed 31 August 2026