If an object is placed 1 meter (3 feet) away from a light source with a lux level of 3200 lux, the lux level decreases according to the inverse square law of light. At a distance of 8 meters (24 feet), the lux level can be calculated as:
New Lux Level=3200 lux(8/1)2=3200 lux64=50 lux\text{New Lux Level} = \frac{3200 \text{ lux}}{(8/1)^2}
= \frac{3200 \text{ lux}}{64} = 50 \text{ lux}New Lux Level=(8/1)23200 lux=643200 lux=50 lux Thus, at 8 meters, the light intensity drops significantly to 50 lux.
Reference: Axis Communications. "Light conditions and surveillance camera performance." Axis Light Conditions.

External (non-integrated) IR illumination can significantly enhance the performance of surveillance cameras in low-light conditions. By increasing contrast in the scene, it allows the camera to capture clearer images with more detail. Additionally, external IR illumination provides more flexibility in placement and coverage, ensuring that the entire area of interest is adequately illuminated. This can be particularly useful in large or irregularly shaped areas where integrated IR might not be sufficient. Axis documentation supports the use of external IR illuminators to improve image quality and scene visibility in low-light environments.