Analogue CCTV cameras designed for cheap and mass surveillance systems aren't very useful in astronomy due to very poor image quality aside of some top shelf or more modern cameras that are actually very good at video astronomy and similar usages. Going with the progress of technology we now have AHD cameras - analogue cameras with higher 720p or 1080p resolution. They cost only 7-15 USD but are they any good and how can we use them?