Backlight compensation provides ideal exposure in front of very strong background light, regardless of the main target moving to the middle, up and down, left and right, or any position on the screen.
An ordinary infrared camera has not only the characteristics of the super dynamic 1/60 second shutter speed and aperture of F2.0 choice, but behind a main target of very bright background or a point source is inevitable, the camera will have all recently light average value and to determine the exposure level, this is not a a good method, because when the shutter speed is increased, the aperture will be closed to the main target becomes too dark without being seen. To overcome this problem, a method called "backlight compensation" is widely used in most cameras by means of weighted region theory. The image is first divided into 7 or 6 regions (two regions are duplicates), each region can be independent of weighted exposure level, such as the middle part can be 9 times to the rest of the block, so a picture in the middle of the target can be seen very clearly, because the exposure is referring to the middle region light grade calculation. There is, however, a very big flaw, and if the main target moves from idle to the upper and lower positions of the picture, the target becomes very dark because it is not differentiated now and has not been weighted.
Q: what is starlight mode?
Starlight mode allows CCD cameras to see clear color images in very weak light conditions, such as 0.0002Lux illumination levels.
All CCD cameras are designed to operate at 1/50,1/60~1/2000 sec shutter speeds, so the minimum illumination level, or sensitivity, is limited to 3 to 6Lux under F1.2 and 5600k conditions. Star model CCD camera proprietary digital signal processor can make CCD shutter speed to 1~10 seconds, because the physical principle of long time shutter, CCD can collect more photons, so more than the traditional camera increased 100 to 600 times the sensitivity.
Q: what are vertical sync, color video, composite signal synchronization, external synchronization, DC line locking, and full synchronization?
This is a different method of synchronization between cameras.
Total locking is the best method of full synchronization between two cameras for precision applications such as broadcast studios and camcorders. It synchronizes: horizontal, vertical, even / odd regions, color triggers, frequencies, and phases.
Vertical synchronization is one of the easiest ways to synchronize two cameras, the vertical driving frequency to ensure the video can be used to switch the old or four stage segmentation machine, display image source on the same monitor. Vertical drive signals are usually composed of repetitive frequency 20/16.7 MS (50/60 Hz) and pulse 1~3 millisecond width pulse.
Color video composite signals represent video and color trigger signals, meaning that the camera can synchronize with an external composite color video signal. However, even though it is called color video composite signal synchronization, there is only horizontal synchronization and vertical synchronization, and there is no color trigger synchronization.
External synchronization is very similar to color video composite signal synchronization. A video camera can synchronize video signals from another camera, and an external synchronization camera can extract horizontal and vertical sync signals using input color video composite signals.
DC line locking is an ancient technology that uses DC 50/60 Hz power line currents to synchronize cameras. Because the DC 24 volt power supply is widely used in most building fire alarm systems, as it is very easy to obtain. Because of the old type switcher and segmentation system without a digital memory function, in order to maintain a stable image, synchronization between cameras is necessary, DC line lock is Camera Synchronization in 50/60 Hz, and the level of correlation between vertical color / time channel signals without constraint will lead to bad color conversion (color design stage), so all the use of AC line lock users inevitably lose good color conversion. Fortunately, now the splitter and 16 channel composite processor and the hard disk video recorder have internal memory to overcome this problem, no longer need the synchronous signal, so the AC line lock may after a number of years will be eliminated.
Q: how far can CCD cameras be minimal? It's 11.5X50 cents
M or 22X23 mm limit?
The size of the CCD camera relies mainly on 4 major components, the size of the CCD sensor, the digital signal processor, the CDS, and the vertical drive. Because these chips must be manufactured by different semiconductor technologies, so it is not possible to merge into a single IC, CCD sensor as the main part, has been significantly reduced, from 2/3 inch to 1/2 inch to 1/3 inch to 1/4 inch and 1/6 inch and 1/7 inch CCD, however the smaller size of the sense of rotation optical properties therefore, CCD has more than 1/6 inch 1/4 inch 1/4 inch a lot worse, so CCD over the years has been the mainstream. A 1/4 inch CCD with 10X10 mm size becomes the main component, digital signal processor, if used 15X15 mm QFPGA package will be greater than CCD, further increase the size of the camera board. Most companies today can only reduce CCD camera sizes to 44X44 millimeters.
Q: what is ultra wide dynamic?
The ultra wide motion allows the camera to see the image in very strong contrast.
Wide motion cameras are several times larger than traditional cameras with only 3:1 dynamic range. Natural rays ranged from 120000Lux to starlight, 0.00035Lux at night. When the camera comes from the room