|
Q
1
: |
What is “IR LED” ?
|
| A : |
Infrared LED can only be detected by special cameras but not bare eyes. IR helps detecting video signal at night without inviting attention.
|
|
Q
2
: |
What is “PC-Based DVR” ?
|
| A : |
Based on Microsoft Windows system assisted with video capturing card.
|
|
Q
3
: |
What is “Standalone DVR” ?
|
| A : |
Is designed based on embedded system (mostly Linux), it is easier to operate for everyday user.
|
|
Q
4
: |
What is “Motion JPEG” ?
|
| A : |
Developed based on JPEG technology, with the ability to record series of motion pictures. MJPEG creates good resolution but suffer from lower compression rate comparing to MPEG4. Thus, MJPEG suffer from large storage capacity requirement.
|
|
Q
5
: |
What is “MPEG4” ?
|
| A : |
MPEG4 is based on recalculation of compression data to transfer data, through detecting picture area variation. Therefore, more compression, less capacity requirement, and higher quality of pictures can be obtained.
|
|
Q
6
: |
What is “H.264” ?
|
| A : |
H.264 is the new international imaging code established by itu-t and iso/iec. The standard was finalized in itu-t as H.264; and further established by iso/iec as 14496-10 (MPEG4 part 10)
|
|
Q
7
: |
What is “D1” ?
|
| A : |
D1 : 704 X 480 (NTSC) ; 704 X 576 (PAL)
|
|
Q
8
: |
What is “Half-D1” ?
|
| A : |
Half-D1 : 704 X 240 (NTSC) ; 704 X 288 (PAL)
|
|
Q
9
: |
What is “CIF” ?
|
| A : |
CIF : 352 X 240 (NTSC) ; 352 X 288 (PAL)
|
|
Q
10
: |
What is “Pixel” ?
|
| A : |
The smallest unit in digital imaging, RGB original color value are included in a pixel.
NTSC=270K, PAL=320K, 270K means 27 thousand pixels are on the CCD, but actual value is 25 thousand pixel (effective pixel).
|
|
Q
11
: |
What is “Resolution” ?
|
| A : |
Vertical resolution：
Vertical resolution is limited by vertical display lines. NTSC design is 525 lines and Pal 625 lines. If using KELL or high width exposure mode, highest vertical resolution is horizontal line multiplied by 75%. Therefore, the maximum vertical resolution is: NTSC: 525x0.75=393; PAL: 625 x 0.75= 470 lines.
Horizontal resolution:
Theoretically, horizontal resolution can can be increased without limitation, but there are two basic constrains from technological limitation. First is the limitation on chip resolution, or even with smaller chips, the light sensitivity is lowered.
|
|
Q
12
: |
What is “Minimum Illumination” ?
|
| A : |
Minimum illumination refers to the visible resolution under the lowest illumination. Lux is the standard unit for minimum illumination, the high Lux the better. Camera F ratio determines the amount of light entering the unit, is also important when choosing a camera.
|
|
Q
13
: |
What is “White Balance” ?
|
| A : |
When objects are white in color, different color will be seen based on lighting. For example, if yellow lights shads on a white paper, the paper will be seen as yellow. White balance will adjust the yellow light and return the wrong color into white.
|
|
Q
14
: |
What is “Auto white balance (AWB)” ?
|
| A : |
Camera will analyze and determine surrounding color temperature. Auto white balance adjusts the color and corrects possible color difference.
|
|
Q
15
: |
What is “CCD Sensor” ?
|
| A : |
Regular camera's CCD sensor, based on resolution can be categorized into 1/2”. 1/3”, and 1/4”.
1/3” CCD sensors can only be equipped on camera size 1/3”, 1/4” or below 1/4”. It will not function on 1/2” cameras, which will cut off partial display on the edge.
|
|
Q
16
: |
What is “Lens Mount” ?
|
| A : |
There are two international standards—CS and C. CS type mount are predominantly used in the market. Basically, the screw trails between CS and C are identical. The difference is the distance between lens and sensor. C type mounts, when comparing with CS mounts, has a 5mm lower focusing range. This is also the main reason why a mount ring is shipped with every camera, to ensure compatibility.
|
|
Q
17
: |
What is “Fixed focal lens” ?
|
| A : |
Fixed focal lens is fixed by lens focus. Normally, there are sizes of 2.3mm, 3.6mm, 4.3mm, 6mm, 8mm, 12mm, and 16mm. The larger the number, the less viewable range the lens provides; and vise versa.
|
|
Q
18
: |
What is “Variable focal lens” ?
|
| A : |
Lens with variable focus points. Normal size range from: 2.8mm~12mm, 3.3mm~8mm, 6mm~15mm, 5mm~50mm, 6mm~60mm. Based on built structure, there are manual and auto focus. Variable focus lens are controlled by additional controllers, 10X lens variability is based on dividing back focus divided by front focus point. For example 6mm~60mm lens has a 60mm/6mm=10X variable focus.
|
|
Q
19
: |
What is “Electronic Shutter” ?
|
| A : |
When cameras encounters strong surrounding light, it can use electronic shutter to reduce sensitivity and reduce amount of light entering the CCD sensor. So over-exposure will be avoided.
|
|
Q
20
: |
What is “IRIS” ?
|
| A : |
Can be divided into fix and auto IRIS. Auto IRIS is transmitted by DC drive, and IRIS will adjust according to light variation. Auto IRIS is divided into two modes, one being Video Driver with built in IRIS engine PCB to adjust according to light. Another being the DC Driver, which adjust with the original circuit design to change in accordance with lighting. Video Driver is more costly whereas DC Driver more economical.
|
|
Q
21
: |
What is “Manual IRIS Lens” ?
|
| A : |
Manual IRIS Lens is adjustable IRIS and Focus, normally being deployed indoor because indoor lighting will not experience dramatic change. This type of lens can be adjust with surrounding lights to achieve the best picture quality. With electronic shutter off, color will be fixed with the best quality possible.
|
|
Q
22
: |
What is “Automatic IRIS lens” ?
|
| A : |
Automatic IRIS lens are lenses that automatically adjust IRIS. Normally being deployed outdoor due to its capability of auto light adjustment. It is important to note that base illumination setting is always needed so the auto adjustment can take effect based on surrounding light. To tell the base illumination is simple. For VIDEO Drive IRIS, locate “LEVEL” and “ALC” marking on the body of camera, adjust the “LEVEL” to achieve the best picture quality. For DC Drive IRIS, simply adjust the “LEVEL” button in the back. When best picture quality is obtained, set “Auto adjust” on.
|
|
Q
23
: |
What is “Automatic Gain Control (AGC)” ?
|
| A : |
When signal deteriorates, activating AGC will enhance display quality and sharpen the picture; nevertheless, signal distortion is relatively bigger as well.
|
|
Q
24
: |
What is “NTSC” ?
|
| A : |
National Television Standards Committee (NTSC) has the standard of 29.97 frame per second, with the TV line of 525.
|
|
Q
25
: |
What is “PAL” ?
|
| A : |
Phase Alternating Line (PAL). It is the TV standard established by West Germany in 1962. It overcomes the limitations of NTSC and have a TV line of 625. PAL TV was used in China and Europe.
|
|
Q
26
: |
What is “VGA” ?
|
| A : |
VGA, (Other names includes RGB, D-sub 15, or mini D15) is three line, 15 pin designed connector for picture output.
|
|
Q
27
: |
Dose video format(NTSC/ PAL) matter ? are they compatible ?
|
| A : |
The two standards are not compatible with each other, picture displayed on a different standard will turn into black and white.
|
|
Q
28
: |
What is “BNC” ?
|
| A : |
Bayonet Nut Connector, BNC Was not phased out because of the shielding that enables signal quality of video and audio data.
 
|
|
Q
29
: |
What is “RS-485” ?
|
| A : |
Serial connector/protocol, mainly used to control PTZ devices such as Speed dome.
|
|
Q
30
: |
What is “Video-in/out” ?
|
| A : |
Cideo-in/out for connecting cameras or other display devices. BNC connectors are widely used. 75 OM cables.
|
|
Q
31
: |
What is “Audio-in/out” ?
|
| A : |
Audio-in such as hidden microphone. RCA connectors are widely used with a 75 OM cable or other audio cables. Audio-out for speakers.
|
|
Q
32
: |
What is “Loop Out” ?
|
| A : |
The splitting of image data when it enters the DVR, one to the DVR board, another to additional device.
|
|
Q
33
: |
What is “Main Monitor” ?
|
| A : |
Main monitor is the main display device used.
|
|
Q
34
: |
What is “Spot Monitor（CALL Monitor）” ?
|
| A : |
Support image display as assisting display device. Certain products carries multiple spot monitor.
|
|
Q
35
: |
What is “S-Video” ?
|
| A : |
S-video interface can be connect to display monitors, TVs, and LCDs.
|
|
Q
36
: |
What is “Alarm-in” ?
|
| A : |
Alarm1 to Alarm 16, for alarm activate features. The simplest way is to use NO/NC features.
|
|
Q
37
: |
What is “Alarm-out” ?
|
| A : |
Alarm-out is by using relays, normally with Out N.C/Out COM/ and Out N.O
|
|
Q
38
: |
What is “eSATA” ?
|
| A : |
eSATA is external hard drive interface for additional storage space
|
|
Q
39
: |
What is “SATA” ?
|
| A : |
DVR internal hard drive storage interface, 2SAN products all use native SATA controller IC, there are no compatibility issue.
|
|
Q
40
: |
What is “Ethernet” ?
|
| A : |
Ethernet interface connects DVR to utilize remote access capability.
|
|
Q
41
: |
What is “USB” ?
|
| A : |
USB controls backup and/or mouse
|
|
Q
42
: |
What is “CF” ?
|
| A : |
Provide backup, support, and software upgrade features.
|
|
Q
43
: |
What is “PTZ” ?
|
| A : |
Pan/Tilt/Zoom’s short hand, represents a 360 degree camera movement. Most DVRs use RS485 protocol, can be achieved with simple wiring.
|
|
Q
44
: |
What is “Pelco-D/Pelco-P” ?
|
| A : |
The most popular protocol of PTZ cameras.
|
|
Q
45
: |
What is “PELCO-D” ?
|
| A : |
Protocol for device communication. Data transfer rate is 2400B/S
|
|
Q
46
: |
What is “PELCO-P” ?
|
| A : |
Protocol uses RS-485 transmission. Data transfer rate is 9600B/S.
|
|
Q
47
: |
What is “IR” ?
|
| A : |
Infrared. Is a wireless communication protocol, capable of transmitting radio signals. IR was widely used since 1974 on mouse, printer, and cameras.
|
|
Q
48
: |
What is “Auto adjustment” ?
|
| A : |
Automatic adjustment according to the light entering the lens.
|
|
Q
49
: |
What is “ATW area” ?
|
| A : |
Auto white balance according to surrounding area’s color temperature.
|
|
Q
50
: |
What is “Lens Aperture” ?
|
| A : |
There are auto and manual types, Auto Aperture will adjust according to camera signals.
|
|
Q
51
: |
What is “A/D Interchange” ?
|
| A : |
Analog to digital signal interchange
|
|
Q
52
: |
What is “D/A Interchange” ?
|
| A : |
Digital to Analog signal interchange
|
|
Q
53
: |
What is “RGB output” ?
|
| A : |
RGB output is the color output of Red, Green, Blue. Composite synchronized signal include the color of green.
|
|
Q
54
: |
Lens mount different? What's the difference between C-mount and CS mount?
|
| A : |
Most CCTV cameras are CS-Mount, CS-Mount cameras can use both C-Mount and/or CS-mount. But C-mount cameras needs additional ring to be able to focus.
|
|
Q
55
: |
What is “MPEG-4 Image compression technology” ?
|
| A : |
It is an advanced image processing technology with high picture quality and compression rate. With low storage consumption, MPEG-4 provide the best picture quality and low storage capacity requirement.
|
|
Q
56
: |
What is “MJPEG Image Compression Technology” ?
|
| A : |
Motion JPEG image processing technology removes unimportant image data to reduce data file size by combining motion display with JPEG technology.
|
|
Q
57
: |
What is “Motion Detect” ?
|
| A : |
Motion detect system monitors abnormal activity (movement) in camera covered area. When motion is detected, alarm can be triggered, which is much more effective than human eye monitoring only. Motion detect also monitors the size and movement speed on objects within range. Motion sensitivity can be adjusted based on movement speed as well as object dimension.
|
|
Q
58
: |
What is “Remote Monitoring” ?
|
| A : |
Monitoring DVR remotely from anywhere, anytime via Internet and PC is remote monitoring.
|
|
Q
59
: |
What is “DDNS” ?
|
| A : |
DDNS automatically matches dynamic IP with specific domain name. DDNS enables dynamic IP user to setup static domain name for www and FTP service. For DVR, this means have a static “address” for remote access.
|
|
Q
60
: |
What is “DNS” ?
|
| A : |
DNS is a system utility software that enables translation between domain name and IP address, which avoids the trouble of memorizing IP address.
|
|
Q
61
: |
What is “DHCP” ?
|
| A : |
A utility software that automatically assigns IP address for TCI/IP network client. The IP assigned by DHCP is dynamic IP. The software is usually seen on router and other network switches.
Through DHCP, router can assign dynamic IP to network clients without setting up static IP for each client.
|
