I have realized that in unwanted cameras, extraordinary receptors help to focus automatically. The actual sensors associated with some surveillance cameras change in contrast, while others start using a beam associated with infra-red (IR) light, especially in low lighting. Higher specs cameras from time to time use a mix of both systems and may have Face Priority AF where the digital camera can ‘See’ any face while keeping your focus only in that. Thank you for sharing your thinking on this blog. bevava