For digital cameras, there are two main factors that affect the image sensor imaging: First, the area of ​​the photosensitive device; second, the color depth of the photosensitive device.
The larger the area of ​​the light-sensing device, the larger the image size. Under the same conditions, more image details can be recorded, and the interference between the pixels is also small, and the image quality is better. However, with the development of digital cameras in the direction of compact fashion, the area of ​​light-sensitive devices can only be smaller and smaller.
In addition to the area, there is an important indicator of the photosensitive device, that is, the color depth, which is the color bit, is how many bits of binary numbers are used to record the three primary colors. The non-professional digital camera's light sensor is generally 24-bit, high-end point sampling is 30, while recording is still 24-bit, professional digital camera imaging device is at least 36, it is said that already has 48 CCD. For a 24-bit device, the light intensity value that can be recorded by the light sensing unit is up to 2^8=256 levels. Each primary color is represented by an 8-bit binary number. The maximum recordable color is 256x256x256. 16.77 million species. For a 36-bit device, the light-sensing unit can record a maximum of 2^12=4096 levels of light brightness. Each primary color is represented by a 12-bit binary number. The maximum recordable color is 4096x4096x4096, which is about 6.87 billion kinds. . For example, if the brightness of the brightest part of a subject is 400 times the brightness of the darkest part, if you use a digital camera that uses a 24-bit photo sensor, if you press the low-light part of the exposure, the brightness is higher than 256 times the parts are overexposed, the level of loss, the formation of bright spots, if you press the highlights to expose, then all the parts below a certain brightness are underexposed, if you use a professional digital camera using a 36-bit photosensitive device, it will not There is such a problem.