Backfocus Mode Detailed information on the time saving enhancements on our standard cameras.  3-CCD Camera Compatability A brief description of the difference between single and 3-CCD cameras. Includes a listing of compatible lenses and cameras Camera/Lens Back Focus Procedure Step by step instructions for setting up the lens and camera for proper tracking. F-Drop Information F-Drop at Wide and Tele. General Troubleshooting A brief description of lens types and installation/troubleshooting tips. Formulas for determining: • Object size at a given distance and focal length. • Focal length needed using a given distance and object size. • Angle of View (field of view). • Depth of Field (Focus). Mechanical vs Optical Back Focal Distance Definition of both terms with drawing. Terminology Lens and CCTV Terminology. Zoom Focal Length Tolerances Focal length tolerances at Wide and Tele.