“ I have observed that in video cameras, unique sensors help to {focus|concentrate|maintain focus|target|a**** automatically. The actual sensors regarding some cams change in in the area of contrast, while others work with a beam associated with infra-red (IR) light, specially in low light. Higher standards cameras from time to time use a blend of both methods and could have Face Priority AF where the digital camera can 'See' a face while focusing only on that. Many thanks for sharing your ideas on this website. ”