27. Noise & Sensitivity

Naturally the noise in the images is very low at normal sensitivity settings (ISO 100 or 200) but increases as you push the sensitivity higher. Our two models can go up to ISO 1600, which is a value that film can only reach with difficulty, and always at the expense of quite a bit of graininess. From this point of view, digital SLRs represent undeniable progress for anyone who shoots in low or very low light.

Below are the details of images shot at different sensitivity settings; admittedly these images are not very meaningful in terms of actual use. When you use a very high sensitivity setting, it's because the lighting is very weak and often poor in quality. That means that in practice, noise will often be much more apparent than in our test images. This is often exacerbated by the need to underexpose and then strongly correct images made under difficult shooting conditions, which increases noise even more.

Still, digital SLRs can produce some very acceptable images under conditions where other photographic techniques become very difficult to use. Needless to say, a compact or bridge camera can't rival them, since their sensors are much smaller and quickly "noise out" as soon as you increase the sensitivity.

100% crop detail of a shot made by the Canon 350D with sensitivity at ISO 200	100% crop detail of a shot made by the Canon 350D with sensitivity at ISO 400
100% crop detail of a shot made by the Canon 350D with sensitivity at ISO 800	100% crop detail of a shot made by the Canon 350D with sensitivity at ISO 1600
100% crop detail of a shot taken by the Nikon D70s with sensitivity at ISO 400	100% crop detail of a shot taken by the Nikon D70s with sensitivity at ISO 800
100% crop detail of a shot taken by the Nikon D70s with sensitivity at ISO 1600