lvguy 0 Posted March 4, 2005 Hi, I'm new to cctv. How do you know if a camera has the ability to use a 2.5mm or 4 mm cs lens? I purchased a cs mount camera and it would only stay in focus with a 6mm lens. Share this post Link to post Share on other sites
AVCONSULTING 0 Posted March 4, 2005 You probably need to adjust the back focus. What camera do you have? Share this post Link to post Share on other sites