Teach you to distinguish the merits of surveillance camera specifications
2023-12-11 23:08:06
How to distinguish the merits of the camera specifications to do selection reference?
This can be discussed from the five major parts:
1. What is the S/N ratio? How to calculate?
2. What is the basic statement of resolution?
3. How is the minimum illumination determined?
4. What is the dynamic range enclosure?
5. What is the degree of color reproduction?
S/N (Signal Noise Ratio) As long as the signal-to-noise ratio is an electronic component, resistance, capacitance, CCD, CDS, and DSP generate heat, and heat affects the image signal, causing noise in the image, and the ratio of image to noise. Is the S/N ratio.
The image is as large as the noise, image noise, and noise (1/1=1): 0 dB;
Image 0, Noise (10/1) = 20dB;
Image ?00, Noise Level (100/1) = 40dB;
Image ? 000, Noise Detection (1000/1) = 60dB;
Image ? 0000, Noise ( (10000/1) = 80dB.
The general specification mentions 48dB, that is, the ratio of image to noise is 300/1 to 250/1.
Reduce the S/N method:
Passive components such as resistors and capacitors, use low S/N, especially CCD, CDS, DSP select low S/N product grade. (taking into account the cost and product level to make a distinction)
Resolution The number of lines that a TV picture can render. The key comes from the CCD/CMOS sensor (?? 0%), ISP and DSP parts? 15-18%, filter? 2-5%. The recognition rate is usually identified by the number of TVL lines in the analog system. IP network cameras use the pixels Pixel as the recognition rate. The HD 720P and Full HD 1080i/P are the recognition rates of the HDTV from the radio and television. The products associated with the recognition rate include the lens and the monitor. The recognition rate must be increased from the front end to the back end. If the camera has 1.3 million pixels, the lens & monitor should have a recognition rate of more than 2 million. Affect the quality of the screen display.
Minimum illumination lux
When the external light falls to a low level, the incoming photon produces a lower voltage than the noise, and the signal is covered by the noise. The smallest light the Sensor can sense is called the minimum illumination.
IRE is the standard of illuminance left?? 0 IRE 0.5 lux, 20 IRE 0.2 lux,...
Ideal lens, F = 1.0, in fact F = 1.2 ~ 1.4 or more, so the lens will eat some light.
Dynamic wide dynamic range: Images viewed from the brightest to the darkest at the same time? The dynamic range is 200 (1 lux to 200 lux) = 46 dB.
Dynamic envelope of 400 (1 lux to 400 lux) = 52 dB
Taking 52 dB as an example, the external 2,000 lux can reduce the aperture to make the internal sensation or 400, but only 0.2 lux is left in the area where the outside is less than 1 lux, and the sensor cannot catch it.
At this time, two shots are taken with two exposure times. Then we take a proper part and synthesize it into a picture we want.
The degree of color reproduction close to the human eye. Generally, Panasonic products can be seen as reddish and SONY as blue, but their respective DSPs will make compensation corrections. This, of course, has a great deal to do with white balance. S, we can talk about it again next time.
When selecting any kind of professional video camera, you can first look at these five parts to make a basic selection reference. It is only necessary to pay attention to the professional part to take special consideration. For example, if you want to have a wide dynamic WDR Camera, then focus on WDR in the evaluation. Do not compare other cameras without WDR, and that imbalance will lose more significance.
Low lux, Day and Night, IR low light, day and night and infrared are separate things. IR Cutter is called True day and night. During the day, the light is filtered by infrared filters with blue filter so that the screen will not be reddish and clear. Remove the filter at night, the infrared light is colorless, so it turns black and white, so that you can see clearly.
In general day and night, a layer of coating is applied to the lens, visible light comes in, and the infrared component (850 to 940 wavelength) comes in. The disadvantages are that the color saturation is insufficient and the infrared light is insufficient at night. However, the price is low, and there is no problem that the organic parts are easily damaged (the mechanical action of the IR cutter movement control).
Low lux: In some places, it is not possible to actively project infrared light. For example, coastal observations and earth observations must rely on natural light sources. In this case, low illumination is required.
On the other hand, IR cams can be used to actively project IR light.
This can be discussed from the five major parts:
1. What is the S/N ratio? How to calculate?
2. What is the basic statement of resolution?
3. How is the minimum illumination determined?
4. What is the dynamic range enclosure?
5. What is the degree of color reproduction?
S/N (Signal Noise Ratio) As long as the signal-to-noise ratio is an electronic component, resistance, capacitance, CCD, CDS, and DSP generate heat, and heat affects the image signal, causing noise in the image, and the ratio of image to noise. Is the S/N ratio.
The image is as large as the noise, image noise, and noise (1/1=1): 0 dB;
Image 0, Noise (10/1) = 20dB;
Image ?00, Noise Level (100/1) = 40dB;
Image ? 000, Noise Detection (1000/1) = 60dB;
Image ? 0000, Noise ( (10000/1) = 80dB.
The general specification mentions 48dB, that is, the ratio of image to noise is 300/1 to 250/1.
Reduce the S/N method:
Passive components such as resistors and capacitors, use low S/N, especially CCD, CDS, DSP select low S/N product grade. (taking into account the cost and product level to make a distinction)
Resolution The number of lines that a TV picture can render. The key comes from the CCD/CMOS sensor (?? 0%), ISP and DSP parts? 15-18%, filter? 2-5%. The recognition rate is usually identified by the number of TVL lines in the analog system. IP network cameras use the pixels Pixel as the recognition rate. The HD 720P and Full HD 1080i/P are the recognition rates of the HDTV from the radio and television. The products associated with the recognition rate include the lens and the monitor. The recognition rate must be increased from the front end to the back end. If the camera has 1.3 million pixels, the lens & monitor should have a recognition rate of more than 2 million. Affect the quality of the screen display.
Minimum illumination lux
When the external light falls to a low level, the incoming photon produces a lower voltage than the noise, and the signal is covered by the noise. The smallest light the Sensor can sense is called the minimum illumination.
IRE is the standard of illuminance left?? 0 IRE 0.5 lux, 20 IRE 0.2 lux,...
Ideal lens, F = 1.0, in fact F = 1.2 ~ 1.4 or more, so the lens will eat some light.
Dynamic wide dynamic range: Images viewed from the brightest to the darkest at the same time? The dynamic range is 200 (1 lux to 200 lux) = 46 dB.
Dynamic envelope of 400 (1 lux to 400 lux) = 52 dB
Taking 52 dB as an example, the external 2,000 lux can reduce the aperture to make the internal sensation or 400, but only 0.2 lux is left in the area where the outside is less than 1 lux, and the sensor cannot catch it.
At this time, two shots are taken with two exposure times. Then we take a proper part and synthesize it into a picture we want.
The degree of color reproduction close to the human eye. Generally, Panasonic products can be seen as reddish and SONY as blue, but their respective DSPs will make compensation corrections. This, of course, has a great deal to do with white balance. S, we can talk about it again next time.
When selecting any kind of professional video camera, you can first look at these five parts to make a basic selection reference. It is only necessary to pay attention to the professional part to take special consideration. For example, if you want to have a wide dynamic WDR Camera, then focus on WDR in the evaluation. Do not compare other cameras without WDR, and that imbalance will lose more significance.
Low lux, Day and Night, IR low light, day and night and infrared are separate things. IR Cutter is called True day and night. During the day, the light is filtered by infrared filters with blue filter so that the screen will not be reddish and clear. Remove the filter at night, the infrared light is colorless, so it turns black and white, so that you can see clearly.
In general day and night, a layer of coating is applied to the lens, visible light comes in, and the infrared component (850 to 940 wavelength) comes in. The disadvantages are that the color saturation is insufficient and the infrared light is insufficient at night. However, the price is low, and there is no problem that the organic parts are easily damaged (the mechanical action of the IR cutter movement control).
Low lux: In some places, it is not possible to actively project infrared light. For example, coastal observations and earth observations must rely on natural light sources. In this case, low illumination is required.
On the other hand, IR cams can be used to actively project IR light.
Circular pop up mosquito net are one of the more commonly used mosquito nets. Ideal for campers and backpackers,circular pop Up bed net folds into a small circular shape for easy packing and carrying. Use on a single bed, mattress, sleeping bag or outdoors.Many summer camps use open air platform tents and circular moving tents. This pop up mosquito net Tent opens instantly and attaches to the bed.
VALUABLE TEXTILE CO., LTD is a comprehensive modern enterprise integrating manufacturing and sales. Since its establishment in 2016, the company has risen rapidly in the Home Textile industry with its professional technical ability and mature craft production level. Valuable Textile Co., Ltd. is a manufacturer which focus on producing different kinds of indoor and outdoor mosquito nets,bed canopy, baby canopies, kid play tents. Every year, VALUABLE exported to over 20 countries and up to 2,000,000 pieces of products to the whole world.
Circular Mosquito Net,Circular Pop Up Bed Net,Foldable Mosquito Net,Circular Net
Valuable Textile Co., Ltd. , https://www.canopiesvaluable.com