Lens Chart


Lens: The lens determines the field of view the camera provides. Lenses range from 2.8mm to 18mm on an average. The larger the lens size the farther it will view. The draw back to a 12mm or 18mm lens is that the horizontal view narrows to as little as 15 feet.

Lens Distance Width
2.8 mm 10 feet 15 feet
3.6mm 30 feet 30 feet
6mm 60 feet 20 feet
  • 2.5mm Lens 120
    2.5mm Lens 120°

  • 3.6mm Lens 90
    3.6mm Lens 90°

  • 4.3mm Lens 78
    4.3mm Lens 78°

  • 6.0mm Lens 53
    6.0mm Lens 53°

  • 12mm Lens 25
    12mm Lens 25°

  • 25mm Lens 18
    25mm Lens 18°

*Many of our customers require a standard fixed wide angle 3.6mm lens. They are designed to be installed in a corner, provide a 90 degree field of view, and provide effective surveillance in a 30 x 30 foot area. If you need to adjust the angle and are not sure when viewing a cash register or looking down aisles, we recommend a vari-focal lens which you can adjust manually based on the angle and distance of the camera to the subject. For example, with a cash register we recommend a 4-8mm vari-focal lens so you can manually adjust and capture the money, hands, and register close up. When in doubt, go with a vari-focal adjustable lens.

Lux and low lighting chart

Condition Illumination Details
(FTCD) (LUX)
Sunlight 10,000 107,527 Daylight
Full Daylight 1,000 10,752.7 Range
Overcast Day 100 1,075.3
Very Dark Day 10 107.53
Twilight 1 10.75
Deep Twilight .1 1.08
Full Moon .01 .108
Quarter Moon .001 .0108 Low Light
Starlight .0001 .0011 Level Range
Overcast Night .00001 .0001

During the day the amount of illumination reaching a scene depends on the time of day and atmospheric conditions. Direct sunlight produces the highest-contrast scene, allowing maximum identification of objects. On a cloudy or overcast day, less light is received by the objects in the scene, resulting in less contrast. To produce an optimum camera picture under the wide variation in light level (such as occurs when the sun is obscured by clouds), an automatic-iris camera system is required. Typically, scene illumination measured in foot-candles (ftcd) can vary over a range of 10,000 to 1 (or more), which exceeds the operating range of most cameras for producing good quality video images. The chart above summarizes the light levels occurring under daylight and these low light level conditions. The equivalent metric measure of light level (lux) compared with the English (ftcd) is given.

 

Lens Size 5FT Away 10FT Away 15FT Away 25FT Away 50FT Away 100FT Away
mm w h w h w h w h w h w h
3.6 7.5 5.2 15.1 10.4 22.6 15.6 37.7 26.1 75.4 52.1 151 104
6.0 3.8 2.9 7.7 5.7 11.5 8.6 19.2 14.4 38.4 28.7 77 57
8.0 2.9 2.1 5.7 4.3 8.6 6.4 14.4 10.7 28.7 21.3 57 43
12.0 1.9 1.5 3.9 3.0 5.8 4.5 9.7 7.5 19.4 14.9 39 30

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