When the light passes through the lens and the shutter is opened, the final image will fall on the sensor. For modern digital cameras, the light will undergo photoelectric conversion in the sensor, and finally the final camera images will be stored in the camera's memory card. After reading the basic workflow of the camera, it is not difficult to find that the soul of a digital camera lies in its sensor, which determines the overall performance and image quality of the camera.
The effect of camera sensor size on noise and image quality:
If we zoom in and look at the camera sensor, we will find that the camera sensor is a rectangular grid composed of millions of small squares, one of which is a pixel. Every pixel has a color, and millions of pixels finally make up a picture. When we enlarge the picture, we will see that this picture contains many small squares, which are the pixels in the picture.
The sensor in the digital camera converts the collected signal light into pixels, each of which contains color and brightness. In theory, the larger the sensor size, the more pixels it contains, and the higher the clarity of the photo. But the actual situation is not like this. When the pixel density is too high, the amount of light acquired by a single photosensitive pixel will decrease. Therefore, the sensitivity must be increased to obtain the same amount of light as the original single pixel, and high sensitivity will produce noise on the picture. Therefore, in our general experience, for a full-frame camera, around 20 million pixels is appropriate.
In general, when the pixels are the same, the larger the sensor size, the better the image quality; and in the case of the same sensor, the pixel and image quality may not be in direct proportion, because the sensor size is the same, increasing the pixel density, and the sensitivity of the picture will also become weaker, resulting in picture noise, thereby affecting the picture quality.