formats are measured in inches: most surveillance cameras fall between
1/4" and 1”. This refers to the usable image size created inside the
camera. For most security use, a small size is fine – 1/4" or 1/3”
cameras dominate CCTV sales. Larger formats do not necessarily result in
better images, but can be advantageous in dimly lit situations since
they are able to gather more light.
Many newer surveillance
cameras use digital signal processing (DSP) to convert the analog video
stream to digital information, improving picture quality and to adding
functionality. The DSP circuit in a camera can have a very large effect
on the quality of the images.