Transparency
Methodology: how we score thermal cameras
Twenty-four criteria, five families, six use cases, fixed and published scoring scales. This page details the formulas, the treatment of missing data, and commercial relationships.
How the ranking is calculated
Each device is scored on twenty-four criteria grouped into five families: sensor and image, optics and spatial resolution, measurement and reliability, usability and reporting, ergonomics and ruggedness. Scores are recalculated on every display from the published specs.
The scoring scales are fixed. Adding a device to the database never changes another device's score, which lets you cite a score and find it again later.
Devices are only compared within their own Segment.
Weightings by use case
| Use case | Sensor | Optics | Measurement | Usability | Ergonomics |
|---|---|---|---|---|---|
| Building diagnostics and energy audits | 30 | 20 | 25 | 15 | 10 |
| Electrical panels and switchgear | 25 | 25 | 25 | 10 | 15 |
| Electronics repair | 30 | 30 | 25 | 10 | 5 |
| Leaks and moisture | 35 | 15 | 25 | 10 | 15 |
| Mechanical and industrial maintenance | 25 | 20 | 30 | 15 | 10 |
| Solar (photovoltaic) | 30 | 25 | 25 | 15 | 5 |
These weightings reflect a technical judgment call, debatable and published for that very reason. The comparator lets you replace them with your own.
Missing data
No value is ever estimated. When a manufacturer does not publish a spec, the corresponding criterion drops out of the calculation and lowers the confidence index.
This index is weighted by the use case being viewed. A missing criterion costs in proportion to its weight in that profile: not publishing a camera's weight hurts a lot for fieldwork and barely at all for solar work. Confidence is therefore specific to each use case, and a device well documented for building work can still be excluded for electronics repair for lack of information about its macro lens.
Three display levels follow from this:
- Above 75%: the score is displayed normally.
- Between 55 and 75%: the score is preceded by the ≈ sign and shown in gray. This is a partial estimate, accompanied by the list of missing specs.
- Below 55%: no score is displayed.
This choice is deliberate: a discreet manufacturer should not receive a bad score, which would suggest a bad product. It should receive a degraded score, or no score at all.
Every product page also shows a raw, unweighted rate: the share of specs the manufacturer actually publishes, across all use cases. It describes the product's documentation and does not depend on any scoring scale.
There is one exception. On criteria that specifically concern the manufacturer's candor, such as the actually measured resolution, not publishing counts as zero rather than being neutralized. Without this, staying silent would pay off more than telling the truth.
What we have not done
The listed devices have not been physically tested. The values come from manufacturer documentation, user manuals, and tests published by third parties, all identified on each product page along with the date they were checked.
There are no user reviews, no editorial score, and no "editor's pick" selection.
Illustrations
All images on this site are original illustrations generated from our own data. No product photograph belonging to a manufacturer or a stock photo library is reproduced.
Price range
Every product page can show an indicative price reference, from € to €€€€€, established from public prices cross-checked on a given date, excluding promotions and any specific retailer. For some industrial or rare models, in the absence of a public price, the bracket relies on a distributor's offer or a similar catalog price. This is not a selling price: it changes, it varies from one retailer to another and depending on configuration (lens, frame rate, kit), and it can be missing for some devices. We fill in this information gradually rather than estimating a value for devices that don't yet have one.
| Symbol | Price range | Approximate positioning |
|---|---|---|
| € | under €200 | Entry level / smartphone |
| €€ | €200 to €500 | Enthusiast / routine diagnostics |
| €€€ | €500 to €1,000 | Mid-range |
| €€€€ | €1,000 to €2,000 | Professional |
| €€€€€ | over €2,000 | High-end / expert |
The positioning shown is a rough market indicator, not a ranking: a device's comparison segment depends on its specs, not its price.
This price range plays no part in any score. This site's ranking relies exclusively on technical specs, whether a device costs €30 or €8,000.
Thermal camera selector: the suitability score
The thermal camera selector starts from a need expressed in plain language and translates it into verifiable rules. It uses no data beyond the catalog and changes no scoring scale: the use-case score it displays is exactly the comparator's.
Conditions that exclude, not points that are deducted
A device is excluded if it fails to meet one of the stated conditions: format (smartphone module, i.e. segment S1, or standalone camera), budget compared to its price range, temperature measurement requested for what is an observation device, discontinued model (unless the visitor includes them), a published minimum focus distance greater than the working distance, or a target more than twice smaller than what the device resolves at that distance.
A device is placed "to check", neither excluded nor ranked, when essential data is missing: price range not determined while a budget is set, field of view not published (spatial resolution cannot be calculated), minimum focus distance not published for work under 30 cm, or documentation insufficient to publish a use-case score. Between 30 cm and 1 m, an unpublished focus distance is merely flagged.
The calculation
The suitability score is 60% the use-case score and 40% a resolution score at the stated distance. This second score compares the target size to the size resolved by the device, i.e. the recalculated IFOV multiplied by the distance. When the visitor needs to read temperatures, the resolved size is multiplied by five, because the smallest surface reliably measurable is roughly five times larger than the smallest visible detail.
| Target ÷ resolved size | Resolution score |
|---|---|
| 4 or more | 100 |
| 1 to 4 | 60 to 100, on a logarithmic scale |
| 0.5 to 1 | 0 to 60 |
| under 0.5 | device excluded |
For work at 10 cm or less, the macro lens is taken into account when it is available and its spot size or smallest measurable area is published. If it is sold as an option, the result card notes it. Devices are then ranked by suitability score, then by documentation confidence.
Default proposed values
Each use case pre-fills a typical distance and target size. These are editorial reference points, shown and adjustable, not measurements.
| Use case | Distance | Target size | Example |
|---|---|---|---|
| Building diagnostics and energy audits | 3 m | 10 cm | thermal bridge, insulation defect |
| Electrical panels and switchgear | 1 m | 2 cm | terminal, connection |
| Electronics repair | 10 cm | 2 mm | component on a board |
| Leaks and moisture | 2 m | 10 cm | pipe path, damp area |
| Mechanical and industrial maintenance | 1 m | 3 cm | bearing, shaft |
| Solar (photovoltaic) | 5 m | 15 cm | faulty cell |
| General-purpose or other use | 1 m | 5 cm | common hot spot |
General-purpose use applies an equal 20% weighting to each of the five families, just as the comparator's sliders allow. Observation devices, which do not measure temperature, never receive a score: they are listed separately and sorted by native resolution.
Limitations
A suitability score depends on the visitor's answers: it cannot be compared from one search to another and is not a general ranking of devices. It accounts for neither the exact price, nor availability, nor any hands-on handling of the devices.
Commercial relationships and ranking
To date, this site has no affiliate links, no commercial partnership, and no payment tied to the listed devices.
If paid links are ever introduced, they will be flagged next to each link concerned and on this page. They will never enter any ranking formula: the calculation uses only technical specs.
Scoring-scale changelog
Every change to a scoring scale is dated and logged. Without this, the promise of stable scores would be worthless.
- v2.5 — 09/16/2026: added the thermal camera selector and its suitability score (60% use-case score, 40% resolution at the stated distance). Use-case scores and scoring scales do not change.
- v2.5 — 09/16/2026: removed a duplicate entry for the Testo 872s, which had no source of its own and contradicted the manufacturer's own datasheet. The catalog now has 139 devices. The entry is archived in data/retires.json.
- v2.4 — 09/16/2026: price range filled in for 137 of 139 devices, from a survey of public and distributor prices (manufacturers, specialist resellers, price comparison sites). Two devices remain ND pending a reference check. No effect on scores.
- v2.3 — 09/16/2026: price brackets expanded from four to five tiers (under €200, €200 to €500, €500 to €1,000, €1,000 to €2,000, over €2,000). Devices whose documented price does not allow a choice between two new brackets revert to ND pending verification. No effect on scores.
- v1.1 — 09/14/2026: the resolution-honesty criterion now scores 0 when a manufacturer advertises interpolation without publishing the target resolution. Previously the criterion dropped out of the calculation, which favored opaque manufacturers.
- v1.1 — 09/14/2026: storage tier set at 90 points for internal memory of 64 GB and above.
- v1.1 — 09/14/2026: the confidence index now excludes criteria marked NA from the denominator.
- v2.0 — 09/14/2026: six use-case profiles instead of five. The "night observation" profile is removed (belongs to monoculars, not measuring cameras). Added "electronics repair", "mechanical and industrial maintenance" and "solar (photovoltaic)". The former "electrical" profile is split: panels and switchgear on one side, boards on the other.
- v2.0 — 09/14/2026: added two macro criteria to family B (capability and minimum measurement size), with internal weights per profile.
- v2.0 — 09/14/2026: drop-resistance anchors become specific to each segment. A 20 g module and a 380 g camera are not judged on the same scale.
- v2.1 — to do: the "micro_balayage_optique" value of the interpolation-method field needs renaming. It now covers two different techniques that genuinely add information: optical micro-scanning and testo's multi-shot super resolution. Both stand in contrast to single-image resampling, which adds nothing.
- v2.2 — 09/14/2026: the confidence index is now WEIGHTED by use case. A missing criterion costs in proportion to its weight in the profile being viewed. Not publishing a camera's weight hurts a lot for the fieldwork profile and barely at all for solar.
- v2.2 — 09/14/2026: confidence becomes specific to each use case. A device well documented for building work but incomplete on its macro lens remains scored for building diagnostics and is only excluded for electronics repair.
- v2.2 — 09/14/2026: three levels instead of two. Above 75%: full score. Between 55 and 75%: score shown as a partial estimate, with the list of missing specs. Below 55%: no score.
- v2.2 — 09/14/2026: the Confidence column in the Calculations tab remains a raw, unweighted rate, identical for all use cases. The site additionally calculates a per-use-case confidence. The two intentionally coexist: the raw rate describes the product's documentation, the weighted confidence decides whether a score is displayed.