What does the MFOV tell you in thermography?

• A. The largest area that can be measured
• B. The average area per pixel
• C. The smallest area to measure
• D. The maximum distance to the target

Answer: (C)

The main idea here is that MFOV, or minimum (measurement) field of view, is the smallest area on the target surface that the camera can resolve as a single pixel. It represents the footprint of one pixel on the object being inspected. This matters because each pixel reports the temperature of whatever area lies beneath it; if the feature you’re trying to characterize is smaller than that footprint, you won’t be able to measure it accurately—the reading will be a blend of that feature and its surroundings.

MFOV changes with distance and lens/optics: moving closer makes the footprint smaller, and using a lens with higher magnification also reduces MFOV. Practically, if you know the MFOV, you can estimate how many pixels a feature will cover and how reliable the temperature reading for that feature will be. If the feature is smaller than the MFOV, it won’t be measured distinctly.

So MFOV tells you the smallest area you can measure.