You can compare resolution to human eyesight. If you have 20/20 vision, you can define the smallest letters at the greatest distance and that’s the equivalent using an infrared camera with a high-resolution detector. A low-resolution detector is the same as a person whose sight is low on the visual acuity scale. The vision is improved by glasses and in the case of the IR camera by adding a magnifying glass to optically reduce its distance from the target.
This enables the camera to take an accurate temperature measurement by allowing it to get more detector pixels on the target, giving more detail in the thermal image. And it’s important to note, digital zoom doesn’t improve accuracy, so higher resolution or also narrow field of view is key here.
Read the full article in the September issue of DPA.