Lens Chart & FAQ's

Lines of Resolution: A Surveillance Camera's performance is based on the number of Horizontal Lines that the Chip in the camera provides. The Lines of Resolution determines the quality of the video the camera can produce. The higher the number of lines of resolution, the better the video quality. As you will notice, we offer Sony Super HAD CCD High Resolution and Super High Resolution Cameras with the newest technology for optimum performance. You will notice that the large majority of our cameras are high and super high resolution. We suggest a high resolution of 480 lines of more for exceptional picture quality.

Performance	Color	B/W
Standard	330 Lines	380 Lines
Medium	420 Lines	470 Lines
High	480 Lines	580 Lines
Super High	540 Lines	600 Lines
Our Newest Technology	680 Lines	700 Lines

Lux (Light) Chart:

 

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. 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. All of our Infrared LED cameras are considered to be rated 0 lux, meaning they can see with zero light. Our Infrared Cameras allow you to see in pitch black conditions. The infrared LED illuminators act as an additional light source for the camera, giving you an image even when natural light sources are absent.

 

 

Lux and low lighting chart
Condition	Illumination		Details
	(FTCD)	(LUX)
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

CCTV Security Pros Camera Lens Chart:

Lens Focal Length

Distance between video camera and the video subject area

5' away

10' away

15' away

25' away

50' away

100' away

mm

Horz area

Vert area

Horz area

Vert area

Horz area

Vert area

Horz area

Vert area

Horz area

Vert area

Horz area

Vert area

2.45

17.3'

13'

34.6'

26'

51.9'

39'

86.5'

65'

173'

130'

346'

260'

2.80

14'

10.5'

28'

21'

42'

31.5'

70'

52.5'

140'

105'

280'

210'

2.97

12.3'

9.6'

24.6'

19.2'

36.9'

28.8'

61.5'

48'

123'

96'

246'

192'

3.60

7.5'

5.7'

15'

11.4'

22.5'

17.1'

37.5'

28.5'

75'

57'

150'

114'

3.70

7.3'

5.5'

14.6'

11'

21.9'

16.5'

36.5'

27.5'

73'

55'

146'

110'

4.0

6.6'

5'

13.2'

10'

19.8'

15'

33'

25'

66'

50'

132'

100'

4.30

6.1'

4.6'

12.2'

9.2'

18.3'

13.8'

30.5'

23'

61'

46'

122'

92'

5.0

4.7'

3.5'

9.4'

7'

14.1'

10.5'

23.5'

17.5'

47'

35'

94'

70'

6.0

3.8'

2.9'

7.6'

5.8'

11.4'

8.7'

19'

14.5'

38'

29'

76'

58'

8.0

2.9'

2.2'

5.8'

4.4'

8.7'

6.6'

14.5'

11'

29'

22'

58'

44'

12.0

1.9'

1.5'

3.8'

2.8'

5.7'

4.5'

9.5'

7.5'

19'

15'

38'

28'

16.0

1.4'

1.1'

2.8'

2.2'

4.2'

3.3'

7'

5.5'

14'

11'

28'

22'

25.0

1'

0.7'

2'

1.4'

3'

2.1'

5'

3.5'

10'

7'

20'

14'

50.0

0.4'

0.3'

0.8'

0.6'

1.2'

0.9'

2'

1.5'

4'

3'

8'

6'

What is a fixed lens and when should I use one?

Fixed lenses usually cover wide angle views regardless of the distance to the subject. If you have a camera in the corner of the room or if you are monitoring a broad and wide area such as outside a home, business, or a parking lot, and you want to pickup as much of scene (field of view) as possible, you would select a wide angle 2.8mm or 3.6mm lens. Most fixed lenses come in a standard wide angle 3.6mm lens. This is a common and cost effective way to monitor an entire room or a broad area outside. If you are covering a wide area, room, or angle then a standared fixed lens (3.6mm) will be perfect and more cost effective.

What is varifocal lens and when should I use one?

A varifocal lens is kind of zoom lens where you have a range of focal lengths you can take. For example 3-8mm lens will allow you to adjust for the field of view you like (within that specified range). In essence, you have may lenses to choose from to get the perfect angle. Varifocal lenses cost more because you have the ability to self adjust the lens. If your camera is in the lobby and you want to watch the door or a cash register, you would use something like an adjustable varifocal lens. The higher the number, the smaller the field of view and there is a bigger zoom effect (objects become closer). So if you think you may want to "get closer" to an object, you may want to choose a varifocal lens to adjust so you can determine the exact angle and ideal width for your application.







DVR FAQ's

What is Frames Per Second and How do I choose?

What is important in evaluating frame rates? Frame rate is one of the most important and one of the most misleading areas when evaluating a DVR. While many vendors provide accurate numbers, there are also many that do not.

30,60,120, 240FPS

Some DVRs specify FPS in increments of 30, 60, 120, and 240. Typically, this refers to the number of frames per second the video capture board can capture. This is not necessarily the same as the number of fps recorded. Further, the fps number is meant to be divided by the number of channels available. For example, one might expect a 120 fps video capture board with 12 channel inputs to provide (120/12) or 10 fps on each channel. Often the actual recorded fps number captured (let alone recorded) is less than 10. The reason is that the capture board may spend some time switching between one channel and the next, resulting in a capture frame rate closer to 8 or 9.

Commonly Observed Frame Rates:

< 1 fps A frame rate of less than 1 fps is too slow for most real world applications. A second is a long time when viewing something in motion and it is likely that a system recording at less than one fps will not be adequate. >= 1 < 4 fps A frame rate of between 1 and 4 fps is extremely jerky, but if it may be a preferred frame rate when combined with a high resolution, such as 4CIF or D1. There is a balance between frame rate and resolution and often resolution is more important when reviewing an event.

>= 5 < 12 fps A frame rate of between 5 and 12 fps is jerky, but adequate for many situations. A frame rate in this range combined with a high resolution, such as 4CIF or D1 is a very good system. Again, there is a balance between frame rate and resolution and often resolution is more important when reviewing an event.

>= 13 < 18 fps A frame rate of between 13 and 18 fps will capture almost all the motion under most circumstances, but the motion will not be as smooth as television. It is certainly noticable.

>= 19 < 30 fps A frame rate of between 19 and 30 fps is smooth by most people's standards. There are many DVRs claiming a full 30 fps that in reality are closer to 20 and most people either cannot tell or are generally satisfied that is television quality.

How many Frames Per Seconds will I see online?

There is no way to tell exactly how fast your video will come across the Internet. The speed depends on your connection to the Internet and the DVR's connection to the internet as well. The DVR's can use any sort of a Ethernet connection but are not compatable with a dial up modem connection.

How many computers can be connected online to view the video from the DVR online?

This depends entirely on the DVR itself. All of our DVRs allow from 5 - 15 people (depending on the model #) view over the internet and cell phone simultaneously.

What are the RCA jacks for on the back of the DVR?

The RCA jacks on the rear of the dvr are for audio (if applicable). Also you will notice both a VGA Connection (PC Connection) and a BNC Connection (for monitor or TV). You may use at least 2 monitors or more with our DVRs and you can customize which cameras you wish to show on each monitor.

What about Technical Support?

Tech support is available by choosing option #2. Hours of support operation are 9 am to 6pm Monday - Friday.



CCTV Security Camera Terms & Definitions

AGC Automatic Gain Control. A circuit for automatically controlling amplifier gain in order to maintain a constant output voltage with a varying input voltage within a predetermined range of input-to-output variation.

AUTO BALANCE A system for detecting errors in color balance in white and black areas of the picture and automatically adjusting the white and black levels of both the red and blue signals as needed for correction.

AUTOMATIC BRIGHTNESS CONTROL In display devices, the self-acting mechanism which controls brightness of the device as a function of ambient light.

AUTOMATIC GAIN CONTROL A process by which gain is automatically adjusted as a function of input or other specified parameter.

AUTOMATIC IRIS LENS A lens that automatically adjusts the amount of light reaching the imager.

BANDWIDTH The number of cycles per second (Hertz) expressing the difference between the lower and upper limiting frequencies of a frequency band; also, the width of a band of frequencies.

BAR TEST PATTERN Special test pattern for adjusting color TV receivers or color encoders. The upper portion consists of vertical bars of saturated colors and white. The power horizontal bars have black and white areas and I and Q signals.

BLOOMING The defocusing of regions of the picture where the brightness is at an excessive level, due to enlargement of spot size and halation of the fluorescent screen of the cathode-ray picture tube. In a camera, sensor element saturation and excess which causes widening of the spatial representation of a spot light source.

BRIGHTNESS The attribute of visual perception in accordance with which an area appear to emit more of less light. (Luminance is the recommended name for the photo-electric quantity which has also been called brightness.)

BROADBAND In television system use, a device having a bandpass greater than the band of a single VHF television channel.

BURNED-IN-IMAGE Also called burn. An image which persists in a fixed position in the output signal of a camera tube after the camera has been turned to a different scene or, on a monitor screen.

CCD See Charge Coupled Device

C MOUNT A television camera lens mount of the 16 mm format, 1 inch in diameter with 32 threads per inch.

CCTV Common abbreviation for Closed-Circuit Television.

CHARGE-COUPLED DEVICE CCD. For imaging devices, a self-scanning semiconductor array that utilizes MOS technology, surface storage, and information transfer by shift register techniques.

COAXIAL CABLE A particular type of cable capable of passing a wide range of frequencies with very low signal loss. Such a cable in its simplest form, consists of a hollow metallic shield with a single wire accurately placed along the center of the shield and isolated from the shield.

COLOR BURST That portion of the composite color signal, comprising a few cycles of a sine wave of chrominance sub carrier frequency, which is used to establish a reference for demodulating the chrominance signal. Normally approximately 9 cycles of 3.579545 MHz.

COLOR SATURATION The degree to which a color is free of white light.

COMPOSITE VIDEO SIGNAL The combined picture signal, including vertical and horizontal blanking and synchronizing signals.

COMPRESSION The reduction in gain at one level of a picture signal with respect to the gain at another level of the same signal.

CONTRAST The range of light to dark values in a picture or the ratio between the maximum and minimum brightness values.

dB Basically, a measure of the power ratio of two signals. In system use, a measure of the voltage ratio of two signals, provided they are measured across a common impedance.

DECODER The circuitry in a color TV receiver which transforms the detected color signals into a form suitable to operate the color tube.

DEPTH OF FIELD The in-focus range of a lens or optical system. It is measured from the distance behind an object to the distance in front of the object when the viewing lens shows the object to be in focus.

DEPTH OF FOCUS The range of sensor-to-lens distance for which the image formed by the lens is clearly focused.

DIGITAL SIGNAL PROCESSING An algorithm within the camera that digitizes data (the image). Examples include automatic compensate for backlight interference, color balance variations and corrections related to aging of electrical components or lighting. Functions such as electronic pan and zoom, image annotation, compression of the video for network transmission, feature extraction and motion compensation can be easily and inexpensively added to the camera feature set.

DISTORTION The deviation of the received signal waveform from that of the original transmitted waveform.

DYNAMIC RANGE The difference between the maximum acceptable signal level and the minimum acceptable signal level.

FIELD One of the two equal but vertically separated parts into which a television frame is divided in an interlaced system of scanning. A period of 1/60 second separates each field start time.

FIELD OF VIEW The maximum angle of view that can be seen through a lens or optical instrument.

FOCAL LENGTH Of a lens, the distance from the focal point to the principal point of the lens.

FOCAL PLANE A plane (through the focal point) at right angles to the principal point of the lens.

FOCAL POINT The point at which a lens or mirror will focus parallel incident radiation.

FRAME The total area, occupied by the television picture, which is scanned while the picture signal is not blanked.

GAIN An increase in voltage or power, usually expressed in dB.

GAMMA A numerical value, or the degree of contrast in a television picture, which is the exponent of that power law which is used to approximate the curve of output magnitude versus input magnitude over the region of interest.

GHOST A spurious image resulting from an echo.

HUM Electrical disturbance at the power supply frequency or harmonics thereof.

INTERFERENCE Extraneous energy which tends to interfere with the reception of the desired signals.

IRIS An adjustable aperture built into a camera lens to permit control of the amount of light passing through the lens.

JITTER Small, rapid variations in a waveform due to mechanical disturbances or to changes in the characteristic of components. Supply voltages, imperfect synchronizing signals, circuits, etc.

LENS A transparent optical component consisting of one or more pieces of optical glass with surfaces so curved (usually Spherical), that they serve to converge or diverge the transmitted rays of an object, thus forming a real or virtual image of that object.

LENS SPEED Refers to the ability of a lens to transmit light, represented as the ratio of the focal length to the diameter of the lens. A fast lens would be rated f/8. The larger the f number, the slower the lens.

LIGHT Electromagnetic radiation detectable by the eye, ranging in wavelength from about 400 to 750 nm.

LOOP THROUGH Also called looping. The method of feeding a series of high impedance circuits (such as multiple monitor/displays in parallel) from a pulse or video source with a coax transmission line in such a manner that the line is bridged (with minimum length stubs) and that the last unit properly terminates the line in its characteristic impedance. This minimizes discontinuities or reflections on the transmission line.

LOSS A reduction in signal level or strength, usually expressed in dB. Power dissipation serving no useful purpose.

LUX International System (Sl) unit of illumination in which the meter is the unit of length. One lux equals one lumen per square meter.

MONITOR A unit of equipment that displays on the face of a picture tube the images detected and transmitted by a television camera.

NTSC Abbreviation for National Television Systems Committee. A committee that worked with the FCC in formulating standards for the present day United States color television system.

OUTPUT The signal level at the output of an amplifier or other device.

PAN AND TILT A device upon which a camera can be mounted that allows movement in both the azimuth (pan) and in the vertical plane (tilt).

PAN/TILT PRESET POSITIONING Follower pots are installed on pan/tilt unit to allow feedback to the controller and provides information relevant to horizontal and vertical positioning, allowing the controller to quickly adjust to a pre-selected scene automatically.

PIXEL Short for Picture Element. A pixel is the smallest area of a television picture capable of being delineated by an electrical signal passed through the system of part thereof. The number of picture elements (pixels) in a complete picture, and their geometric characteristics of vertical height and horzontal width, provide information on the total amount of detail which the raster can display and on the sharpness of the detail, respectively.

PRIMARY COLORS Three colors wherein no mixture of any two can produce the third. In color television these are the additive primary colors red, blue and green.

RESOLUTION (HORIZONTAL) The amount of resolvable detail in the horizontal direction in a picture. It is usually expressed as the number of distinct vertical lines, alternately black and white, which can be seen in a distance equal to picture height.

RESOLUTION (VERTICAL) The amount of resolvable detail in the vertical direction in a picture. It is usually expressed as the number of distinct horizontal lines, alternately black and white, which can theoretically be seen in a picture.

ROLL A loss of vertical synchronization which causes the picture to move up or down on a receiver or monitor.

SATURATION In color, the degree to which a color is diluted with white light or is pure. The vividness of a color, described by such terms as bright, deep, pastel, pale, etc. Saturation is directly related to the amplitude of the chrominance signal.

SHUTTER Ability to control the integration (of light) time to the sensor to less than 1/60 second; e.g: stop motion of moving traffic.

SIGNAL-TO-NOISE RATIO The ratio between useful television signal and disturbing noise or snow.

SHOW Heavy random noise.

SPIKE A transient of short duration, comprising part of a pulse, during which the amplitude considerably exceeds the average amplitude of the pulse.

STANDARD MINIMUM SIGNAL 1000 microvolts at 75 ohms (0dB mV) in RF systems; 0.7-VPP non-composite, 1-VPP composite in video systems.

TEARING A term used to describe a picture condition in which groups of horizontal lines are displaced in an irregular manner.

TEST PATTERN A chart especially prepared for checking overall performance of a television system. It contains various combinations of lines and geometric shapes. The camera is focused on the chart, and the pattern is viewed at the monitor for fidelity.

VERTICAL RESOLUTION The number of horizontal lines that can be seen in the reproduced image of a television pattern.

ZOOM To enlarge or reduce, on a continuously variable basis, the size of a televised image primarily by varying lens focal length.

ZOOM LENS An optical system of continuously variable focal length, the focal plane remaining in a fixed position.