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Infrared Ray |
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Invisible ray with a wavelength between 755nm and 1500nm. |
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Radiation transfers itself to thermal images and thermal unit. |
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Why Night Vision? |
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Infrared is the medium to enable CCD camera night vision in the dark. |
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CCD day & night camera receives the invisible light to view whatever
the human not possible to see at night. |
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Lux |
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The SI unit if illumination |
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Illuminating requirement for a camera |
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Fewer lux, better sensitivity |
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Minimum lux of b/w camera goes ten times fewer than color camera in the same condition |
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Lux levels in various conditions: |
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| 100,000 lux in the sun |
1,000 lux in film studio |
| 10,000 lux outdoor cloudy |
10 lux dusk indoor |
| 100 lux in fluorescent light |
0.1 lux in street lamp |
| 300 lux within 60 cm in light bulb |
10-15 lux in 20 cm candlelight |
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Color camera works between 0.0004 lux to 1 lux.
B/W camera works between 0.0003 to 0.1 lux
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IR LED camera can view images in zero lux condition |
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Lower aperture lens requires fewer lux |
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Notice |
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Best 500mA power supplies in use |
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Target object must be standing within valid range of infrared ray |
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Eclipse camera? |
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Ordinary camera averages brightness of the full screen. Object becomes
dim against strong light opposite.
Eclipse camera can eclipse the strong light to prevent objects from dimming.
License plate beside head light becomes readable when eclipse camera in use. |
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License plate specialty |
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License plate specialty uses shining spot instead of average value to
determine exposing index.
That is to say, we capture a shining spot of its details and color at night.
That is definitely useful in application of license plate recognition and traffic
light capture. |
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What is White Balance? |
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Color changes because the light reflects on objects. Color temperature of picture goes various subject
to different condition. For example, picture becomes yellowish under light bulb. CCD cannot automatically
adjust light change. White balance feature can adjust the images in the picture. It changes the tension of
red, green and blue to balance outer light. Not only auto white balance and color temperature balance, some
cameras also feature manual white balance. |
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Difference between CCD and CMOS images sensor? |
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CCD and CMOS are different image sensors. |
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CCD and CMOS are lighting sensor circuit device. They digitalize the sensitivity of every element
against lighting. |
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Number of pixel is also resolution of CCD. It tells us the number of sensor element. |
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Pixel is the unit of CCD and CMOS. Denser pixel is another word of higher resolution.That is to say
, high resolution camera comes with more pixel than normal camera. Contrast with CMOS, CCD
captures better image quality. It requires much advanced production technology, more power
consumption and much more expense. |
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CMOS is rather a cost effective and few power consumption device. |
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Major CCD suppliers, Sony / Sanyo/ Panasonic / Sharp / Toshiba, are originally from Japan. |
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