I am reading many texts where mates discuss about noise, noise source, noise theory, noise distribution and noise of noise.
But I think that many people are forgeting the eletronic noise caused by the transistors. No mater if it is integrated circuit or an old single transistor. There is noise with solid state components. More than the old vacuum tube.
And just because this you need high refrigeration of solid state electronic circuits.
I understand as native ISO of a camera the area linear of the amplifier, where these noise is with less value to SN rate. The noise is constant up to 60-70 % of the curve of amplification. After that position you enter in the distorted curve area of the amplifier, where the signal has less amplification than the noise generated. Is the condition near of saturation level of solid state electronic compoments.
People that work only with photography don't consider those issues. But when you use the camera as plain people you see it very well. The same time, same object, same place, same luminosity, same camera, same sensor, same all things... and if you change from ISO 100 to ISO 6400 you perceive the increment of noise in the photo.
Many of noise sources are equals, and generate the same intensity of noise. The unique thing really different is the amplification, made by the amplifier.
All knowledge of sources of noise discussed are very important. And can be used to improve the quality of a capture.
But as our automobile, car, even with the best mechanics, you need gasoline. Your car stop to work. Doesn't want to work again. First question: Is there gasoline in the tank ?
The best sensor, used by NASA, if the amplifier is a trash... the photo will be a trash. The amplifier is the gasoline to car. Bad quality... bad performance.
The other electronic task inside the cameras: convertion analog/digital doesn't cause many noise. It only can limit the range of information: 8 bits, 12 bits, 14 bits or n bits
Conclusion:
quality of the sensor and the electronic amplifier are the most important factors. People only discuss about the sensor and its characteristics.
Richard, the text of the link seems to be very good about the noise. I will copy to my computer and read it again with more attention.
If we can not deal with the quality of the amplifier, we must manage very well the others factors that harm our photos.
note: if the camera is a trash... no knowledge about noise will help
Will be it the case of my Canon 1100D with the red channel noise issues ?
