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The Thermogram

Free technical calculator

Thermal camera IFOV calculator

Enter the horizontal field of view, native detector width and working distance. The calculator returns angular IFOV, one-pixel footprint and practical 3× and 5× target sizes.

Your camera and distance

Results

Angular IFOV
One-pixel footprint
3× target size
Conservative 5× target size

3× versus 5× IFOV

3× IFOV is a commonly used minimum spot-size approximation: the target covers several detector pixels. 5× IFOV is the more conservative rule used by The Thermogram selector when temperature measurement matters. It allows more margin for alignment, focus, optics and thermal contrast.

Neither rule replaces the manufacturer's published distance-to-spot guidance, focus limit or macro specification.

Calculate the maximum distance for a known target size →