It might happen that the camera delivers good images during the day, but as soon as it gets darker, people or moving objects become very blurry.
Most probably this is due to the combination of a poorly lit area together with longer exposure times. In those cases, motion blur will occur.
The reason is that unlike the human eye, the camera is able to control the amount of light that hits the sensor by acting on the exposure time. In other words the camera decides how long the pixel should charge before reading their value and consequently discharge them. To darker scenes correspond longer exposure times and therefore moving objects will become blurry as they are moving while the pixels are charging.
Motion blur can be reduced, up to a certain degree, by shortening the exposure times (e.g. from 1/5s to 1/30s), but this will result as well in a darker image and a compromise needs to be found.
Motion blur can be reduced to a certain degree by shortening the exposure time or, preferably, by increasing the illumination. Moreover, when possible, it’s advisable to use Night sensors due to the fact that they have a much higher sensitivity compared to the Day ones.
MOBOTIX offers new 6MP sensors with Moonlight technology that minimize the need for artificial light and solve in most cases the motion blur caused by poorly lit scenes.
Depending on the sensor module, it is possible to use IR light with a wavelength of about 850nm (for night or LPF sensor models only!) or visible light for day sensor modules.