Situating your camera so that you capture the exact footage you require for the purpose you need it for is essential in a good CCTV system design. Weather you are looking to monitor & control, detect, observe, recognise or identify… here is a general guide to help you.
These image sizes are an approximation and are relative to the size of the monitor being used. It does not necessarily mean that it is impossible to recognise an individual that occupies less than 50% of the screen, and equally there is no guarantee that an individual that occupies more than 100% of the screen will be identifiable. Other factors may also affect identification such as the lighting or angle of view, and file compression can lead to loss of picture quality compared to Live View.
Please Note: that these guidelines are set for analogue PAL systems and therefore may not translate equally for HD-SDI and IP systems.
Data source: HOSDB 55/06