Why fiber optic used in CCTV system?

Most closed circuit TV uses coaxial cable, not fiber although larger systems are increasingly using fiber components.

Currently, quality is limited by the availability of cameras, switchers and recorders in the security and monitoring market so the use of fiber has limited benefits. However, there are installations that use it to prepare for the higher data rates of future HD systems, to support longer signal routes than copper supports easily and to make use of fiber based infra-structure that is already in place.

Although the future upgrade path can justify the extra expense, in some cases, it is simply an expensive method of achieving the same result as a copper installation.