rory 0 Posted March 1, 2004 as a general rule, what is the farthest distance you can make out a persons face at, using different lenses? i was thinking maybe 50' max no matter what lens, from the start of the lens focal point, at the center of the lens? Rory Share this post Link to post Share on other sites
AVCONSULTING 0 Posted March 1, 2004 The distance is unimportant as long as you use a proper focal length. Rule of thumb is to have a a FOV of 20' wide. Share this post Link to post Share on other sites
rory 0 Posted March 1, 2004 yeah but if the person is 50' from the camera, or lets say 75' using a 4mm lens then its hard to see their face. What im asking is regardless of which focal length used, say if youare using a 8-10mm and they are 125' away, there is a limit to how far the camera will see. What im asking is what is the normal distance that you can capture a face from the start of the lens focal length? Like if the clients should have say 3 cameras but only want 2, but with 2 they will not see as much/far as they could using 3. Rory Share this post Link to post Share on other sites
AVCONSULTING 0 Posted March 1, 2004 Use a 25mm lens for 125 distance to get 20' wide. There is no limit to how far a camera can see given the proper lens, after all you've used domes before and probably could zoom in 300' away to read a license plate. I would say that the maximum you could get away with might be 50' wide, but I think you need to test that. Share this post Link to post Share on other sites
rory 0 Posted March 1, 2004 yeah I know, but if they want to see directly below or near the camera, then they need at least a 4mm, but then they wont see as the persons face beyond 50' thats what Im trying to find out, what is the normal distance, say using a 4mm lens then. I know with my 3.6mnm bullet I cant make out a persons face 'clear' beyond like 30 feet. Rory Share this post Link to post Share on other sites
AVCONSULTING 0 Posted March 1, 2004 Rule of thumb with a 1/3" camera and a 4mm lens. Distance = Width. So if you have someone 50' away from the camera you will have a 50' wide FOV. Make sure your bullet isn't a 1/4". Share this post Link to post Share on other sites
CCTV_Source 0 Posted March 5, 2004 Don't forget to take the DVR into consideration as well. If your DVR let you watch live feed in 4CIF but is only capable of recording in CIF, then the nice recognizable face on the spot monitor is shown with twice as many lines as are actually being recorded. Share this post Link to post Share on other sites
