What are the differences in imaging quality of images at different gains of industrial cameras?

The general meaning of gain is simply the amplification factor. In electronics, it is usually the ratio of the signal output to the signal input of a system. For example, antenna gain represents the parameter of the radiation concentration of a directional antenna. It is the ratio of the square of the electric field intensity generated by a directional antenna and a non-directional antenna in a predetermined direction. The amplifier gain represents the amplifier power amplification factor. It is expressed as a common logarithm of the ratio of output power to input power.

The imaging quality of industrial cameras is different at different gains. The smaller the gain, the smaller the noise; the larger the gain, the more noise, especially in dark places. Gain is called gain in industrial cameras. In civilian digital cameras and SLRs, it has a more commonly used name called ISO. The larger the ISO, the greater the gain and the more noise in the image. When evaluating camera products from various manufacturers, the imaging quality under high-gain conditions is often evaluated first.

Gain is generally only used when the signal is weak but you do not want to increase the exposure time. Generally, camera gain produces a lot of noise, so it is rarely used. Of course, EMCCD talks about it separately. Among them, exposure and gain are the data read out from the direct control sensor (CCD/CMOS). They should be adjusted first, mainly adjusting the exposure time. Without overexposure, increasing the exposure time can increase the signal-to-noise ratio and make the image clearer. There is an option in the software to display overexposed areas. Of course, for very weak signals, the exposure cannot be increased indefinitely, because noise will accumulate as the exposure time increases. The so-called cold CCD relies on cooling to reduce noise, so that it can capture weak signals with long exposures.