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Lens Info

CCTV Lens LUX Chart

CCTV Visual Lens Comparison Chart

CCTV Technical Lens Comparison Chart

35mm to CCTV Focal Length Conversion Chart

How to select a proper security camera lens in 3 easy steps and save money doing it?

1. Should I use Manual Iris, Auto Iris or DC lens?

You can save money and use manual iris lens only when scene illumination never changes. Example: illuminated store or office.
If the light changes a lot it is recommended using auto-iris

2. What focal length lens do I need?

Guide: smaller the focal length number => wider is field of view.
If you have securit camera in the office or warehouse and you want to see as much as you can, you should go for 2.8 or 4 mm lens (makes wide, somewhat distant view)
If you want to observe limited area, like entrance you should go for 8mm or (makes narrow view and objects are closer).
Give us a call and we can help you determine what security camera lens will best suit your location.
Use varifocal lenses to get flexibility for choosing best field of view.

The CCTV security camera lens chartand field-of-view diagrams are designed to assist you in selecting the right lens size for your application. Please contact us if you require additional information or assistance. Keep in mind all of the security cameras we sell come equipped with lenses that will achieve 95% of your surveillance applications.

CCTV Lens LUX Chart

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

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.

CCTV Visual Lens Comparison Chart

The following chart displays the comparision of CCTV lens with the regular 135mm film camera lens.

CCTV lens		135mm lens
Focal Length	Angle	Angle	Focal Length
2.5mm	120�	114�	14mm
3.6mm	92�	94�	20mm
4.3mm	78�	75�	28mm
6.0mm	53�	51�	45mm Standard lens for 135mm camera Regular angle of our eyes vision
12mm	25�	24�	100mm
25mm	18�	18�	135mm

CCTV Technical Lens Comparison Chart

Indicates total viewable area (WxH) at a given distance based on focal length used

Focal Length	5' (WxH)	10' (WxH)	20' (WxH)	40' (WxH)	50' (WxH)	100' (WxH)
2.5 mm	9.4x7.1	19x14	38x28	75x57	94x71	188x142
2.9 mm	8.6x6.4	17x13	34x26	69x51	86x64	171x129
3.6 mm	6.9x5.1	14x10	27x21	55x41	69x51	137x103
4.0 mm	6.0x4.5	12x9	24x18	48x36	60x45	120x90
4.3 mm	5.7x4.3	11x8.6	23x17	46x34	57x43	114x86
5.5 mm	4.5x3.4	9x6.8	18x14	36x27	45x34	90x68
6.0 mm	2.0x1.5	4x3	8x6	16x12	20x15	40x30
8.0 mm	1.5x1.1	3x2.3	6x4.5	12x9	15x11	30x22
12.0 mm	1.0x0.7	2x1.4	3.8x3	7.7x6	9.6x7	19x14

Use your 35mm camera and this chart to help make your lens decision.

35mm to CCTV Focal Length Conversion Chart

35 mm	1/4"	1/3"	1/2"	2/3"	1"	Angle
10	0.9	1.4	1.8	2.5	3.7	120.6
35	3.2	4.8	6.4	8.8	12.8	53.2
60	5.5	8.2	11.0	15.1	22	32.6
85	7.7	11.6	15.6	21.3	31.1	23.3
110	10.0	15.1	20.1	27.6	40.3	18.1
135	12.3	18.5	24.7	33.9	49.4	14.8
160	14.6	21.9	29.3	40.2	58.6	12.5
185	16.8	25.3	33.9	46.4	67.7	10.8
210	19.1	28.8	38.4	52.7	76.9	9.5
235	21.4	32.2	43.0	59.0	86.0	8.5
260	23.7	35.6	47.6	65.3	95.2	7.7

CCTV focal length numbers shown converted from a 35mm camera zoom lens.

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