Spot Size & Distance Calculator (IFOV)
Use your camera’s IFOV (mrad) to estimate spot size at distance. Helpful for knowing whether a lug, conductor, or termination is large enough to measure accurately.
Thermal camera distance reading is commonly in meters.
Find IFOV in your camera specs (often listed as “IFOV” or “spatial resolution”).
If entered, you’ll get a quick “OK / Too Small” indicator.
Spot size (diameter)
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Recommended minimum target
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Rule-of-thumb: target should span at least 3 pixels (conservative) for better accuracy.
Target check (if provided)
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Note: This is an estimation tool. Real-world accuracy can be affected by focus, lens, atmospheric attenuation, reflected temperature, and emissivity.