What does auto focus camera noise mean?

The so-called noise refers to the noise, because the automatic focus camera imaging principle, resulting in imaging will produce a lot of noise points, these noise points constitute the noise. Generally speaking, the better the sensor, the more advanced the algorithm in imaging processing, and the less noise. This is why the noise of a DSLR is significantly better than that of a home DC. In addition, the noise is closely related to ISO, the higher the ISO, the heavier the noise. For the noise, we can remedy it by the way of noise reduction in the later stage, and the effect is good.

According to the European camera test standard EMVA1288, the noise defined in the camera can be generally divided into two categories:

One is the statistical fluctuation noise brought by the effective signal in line with the Poisson distribution, also called shot noise (shot noise), this noise is the same for any camera, inevitable, and especially determined formula. (That is, the square of noise = the mean of the signal).

The second type is the camera itself inherent noise unrelated to the signal, which is caused by the image sensor readout circuit, camera signal processing and amplification circuit, etc., the inherent noise of each camera is different.

In addition, for the digital camera, the analog conversion of the video signal will produce quantization noise, the higher the quantization number, the lower the noise.

SONY auto focus cameras all feature 2D or 2D/3D noise reduction, making the picture more clear and delicate.