When taking pictures with a SLR camera, there are many miscellaneous points. What is the reason?

1. Generally speaking, the higher the sensitivity of a digital camera, the more serious the noise, but it does not mean that there is no noise at low sensitivity (such as ISO 100);

2. The working principle of digital camera is that the lens emits light, the sensor converts light elements into electrical signals, and the image processor converts electrical signals into electronic documents. In the process of photoelectric conversion, the sensor will inevitably produce thermal noise, that is, noise, but to different degrees;

3. In addition to the difference in sensitivity, noise is also related to pixels per inch, which is the signal-to-noise ratio of digital imaging. Generally speaking, the fewer pixels per unit area and the lower pixels per inch of the sensor, the better the signal-to-noise ratio index. On the contrary, the signal-to-noise ratio index is poor, and the difference reflected in the photo is noise. Of course, the RGB color separation technology of the sensor is also related to the purity of color, which is a factor of manufacturing technology and has nothing to do with the camera;

4. Nikon D3200 uses a half-frame 24-megapixel sensor with higher pixels per inch, and the image purity will be worse than that of Quan Huafu's16-megapixel sensor. This is normal, and there is nothing wrong with the camera and lens, which has nothing to do with the light at the scene.

5. It is suggested to turn off "dynamic D-Lighting" and "long exposure noise reduction" in the menu to minimize the appearance of noise.