The following photos show different focal length lenses on a cctv camera pointing down a 35 foot
hallway.

Dist (ft) 3.5mm 8mm

10 9v/12h 4v/5h
15 13v/18h 6v/8h
20 19v/22h 8v/11h
25 22v/30h 10v/13h
30 27v/33h 12v/16h

(coverage is expressed in feet vertical and horizontal)

Dist (ft) 4mm

10 8v/11h
15 12v/16h
20 16v/22h
25 20v/28h
30 22v/32h

Dist (ft) 6mm

10 5.5v/7.5h
15 8v/11h
20 11v/15h
25 14v/18h
30 17v/22h

Dist (ft) 15mm

10 2.2v/3h
15 3.2v/4.5h
20 4.2v/6h
25 5.5v/7.5h
30 6.5v/8.5h
35 7.5v/10h
40 8.5v/12h

50 11v/14h

Telephoto Lens Coverage

Dist (ft) 50mm 60mm

30 2v/2.5h 1.5v/2.1h
40 2.5v/3.4h 2.2v/3.0h
50 3.0v/4.2h 2.6v/3.6h
60 3.8v/5.0h 3.2v/4.2h

Wide Angle Coverage

Dist (ft) 2.5mm

10 14v/18h
15 20v/28h
20 28v/37h
25 34v/46h