With more cameras will slowly understand what factors determine the camera imaging effect, Xuan Zhan technology this time to sort out a few small points, specifically for the majority of white users, I hope it will be helpful.
Camera resolution and contrast play an indispensable role in imaging systems. While camera resolution and contrast may look like optical parameters, pixel number and size, TV line, pixel depth/gray level, dynamic range and SNR help the user understand the quality of the imaging. For technical tips on each important parameter, the camera resolution can be understood from novices to experts as it relates to the imaging electronics of the system. Next, Xuan Zhan will analyze for you what factors determine the imaging effect of the camera?
① Number of pixels and pixel size
To get an idea of the number of pixels and pixel size of your camera, consider the SONY FCB-EV7500, SONY’s FCB-EV family of products covers the 10x to 30x optical zoom range, HD to full HD. All of these camera movements inherit the features of SONY’s world-class FCB series, such as automatic ICR, spherical privacy area shielding and anti-fog functions. In addition, SONY’s FCB-EV series camera movement lineup introduces two high-sensitivity, high-quality camera movements, FCB-EV7520 and FCB-EV7320, which use 1/2.8 inch Exmor R? CMOS sensors that deliver full HD video and extraordinary sensitivity. These camera movements use STARVIS technology to achieve high picture quality in visible and near infrared light.
② The more pixels, the better the resolution in the field of view (FOV)
However, a large number of pixels requires either larger sensors or smaller sized individual pixels. Using a larger sensor to achieve more pixels means that the imaging lens is enlarged and/or the field of view changes. In contrast, if smaller pixels are used, the imaging lens may not be able to maintain the resolution of the system due to the limited spatial frequency response of the optics, mainly caused by design issues or the diffraction limit of the aperture. The number of pixels also affects the frame rate of the camera.
③ Pixel depth/gray scale
Often referred to as the gray level, or the dynamic range of a CCD camera, the pixel depth represents the number of steps of the gray level in the image. At unit gain, light with 100% saturation of pixels will be given a value of 2N − 1, where N is the number of bits, and the digitization process is smoother. In addition, more bits mean higher precision and more information. With enough bits, the human eye can no longer determine the difference between successive gray levels and their digital representation.
④ Dynamic range
Dynamic range is the difference between the lowest detectable light level and the highest detectable light level. Physically, this depends on the saturation capacity of each pixel, dark current or dark noise, ADC circuit and gain Settings. For high dynamic range, more bits are needed to describe the gray level in a meaningful way. However, it is important to take into account the SNR that using 14 bits to describe a dynamic range of 50dB gives redundant bits without additional information.
⑤ Signal-to-noise ratio (SNR)
The signal-to-noise ratio (SNR) is closely related to the dynamic range of the camera. The higher signal-to-noise ratio produces a higher number of steps in the gray scale (higher contrast) produced by the camera. The signal-to-noise ratio is expressed in decibels (dB) of analog systems and bits in a digital system. In general, 6dB of analog SNR is converted to 1 bit when digitized. For digital or analog cameras, X bits (or their equivalent in analog systems) correspond to 2Xgrayscales (that is, 8-bit cameras with 28 or 256 gray levels).