Noise in digital photography, Lloyd Godman aesthetics

With digital, as we increase the ISO noise becomes present in the image. This is most noticeable in large ares of even tone and more so in the shadow areas. It shows in the shadows more as there is less digital information in these areas. In this simplified illustration there is 10 shades of grey in the shadows and this doubles as we progress to the light end of the tonal scale where much more digital information is recorded, however, white has no digital information. We see this in the top corners of the image on the right where there was little light in the scene and the image is shot hand held at 6500 ISO. In film based photography with film, this becomes obvious in the same way but is termed GRAIN.
When we open an image with a raw file converter, as in Bridge we have the option of reducing the noise, we click the third option DETAIL > and use the controls at the bottom noise reduction.

Here we see a close up of the top right section of the image that illustrates the noise in the original image	Here we see the same close up of the top right section of the image that illustrates the noise reduction of the original image

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