Noise is that undesirable grainy-look in the signal especially when working with low-light conditions, therefore our first recommendation would be to add the maximum of light when possible!
But if not due to poor lighting, the noise may also be due to electromagnetic interferences around or bad infrastructure: poor quality cables, power supplies (proper voltage and current? our cameras usually require 12V2A), converters, connections, incorrect grounding..
Also the choice of the camera sensor has its importance here because the larger the camera's image sensor the better the image in low-light conditions. But don't worry, our Avonic camera sensors are enough big to still deliver outstanding quality under low light conditions
If you look inside the camera configuration, you will find the support of some "Noise Reduction" options that help to decrease the noise:
[OSD] -> [CAMERA] -> [NOISE REDUCTION]
[Web GUI] -> [VIDEO] -> [Camera Settings] -> [NR]
NR stands for Noise Reduction. The NR options can be used to soften the image when noise is created by the sensor normally due to poor lighting conditions or when it has not been properly setup. Concretely they help to remove the grainy appearance of low-light images, handle moving objects without leaving trails, and make images clearer and sharper. Plus removing noise will help to reduce the size of the signal!
Be careful, the higher the amount of noise reduction, the softer the image will get, ultimately resulting in loss of details!
-NR-2D (Temporal Noise reduction) analyzes each pixel in each frames to isolate & replace the noise pixels. 2D is more expected for low resolution images and/or with stationary objects or people to film (otherwise it might blur the moving objects and leave motion trails behind)
-NR-3D (Spatial Noise Reduction) uses a frame-on-frame method of comparison to detect motion more accurately. It is better at removing grainy appearance than 2D but especially more with higher resolution and/or with moving objects.
It is however possible to use them both at same time to create a crisp and clear image!
* Dynamic Hot Pixel: a defective pixel is a pixel which looks much brighter than it should and will sometimes become visible due to long exposure shots of the camera at a higher rate of light sensitivity or when the CMOS sensor is too old. This issue can be sometimes visible as sparkles in the picture. The Dynamic Hot Pixels mode should correct these defective pixels to appear as normal on the filmed picture.
Be careful when adjusting the noise reduction, as it can take away the natural ‘crispness’ of the image (the same happens if you set the dynamic contrast and gain too high which at the end will cause more noise!). It's always better to add more light to the filmed object when possible.