High-sensitivity image sensors
For a security camera, what matters most is how the sensor copes with low light and with infrared light from the illuminator. High-sensitivity sensors with a Back-Illuminated (BSI) construction place the control electronics behind the light-sensitive layer, not in front of it. More light reaches the photodiodes, so sensitivity improves in both the visible and the infrared spectrum (850 nm).
What it means in practice
PATRONUM cameras benefit most in poor lighting. With normal street lighting they often do not need to switch to black-and-white night mode — even a little light is enough for a colour image. Sensor size and minimum illumination in lux are listed in the specifications of each camera.