To measure and compare the Nikon D40's noise levels we photographed the standard Gretag Macbeth ColorChecker with it and a number of rival models using their best quality JPEG and default image tone, sharpening and noise reduction settings. The D40's noise reduction is off by default, but we have also included swatches with it enabled for comparison.

The crops are taken from the original images and presented here at 100%. To compare typical noise in skies and dark shadows the crops were taken from patches 3 and 24 respectively.

The Nikon D40 delivers very clean images which are essentially noise-free at 200 and 400 ISO and only show the slightest noise at 800 ISO. Up to this point, it arguably performs better than both the Canon EOS 400D / XTi and the Nikon D80.

At 1600 ISO, some texture through noise and processing is apparent, but it's still relatively clean and superior to the Canon result. At 3200 ISO, noise levels increase significantly, although they're still acceptable for smaller print sizes in emergency situations. Note due to their higher resolutions, the Canon 400D / XTi and D80 crops represent a smaller portion of their overall frames, and hence any artefacts below appear slightly larger and more obvious.

That said, the D40 still delivers impressively low noise in this test, although as always you should also compare noise levels with real-life subjects. As you'll see in our Nikon D40 Gallery for example, the camera performs well across its entire ISO range, proving increased megapixels aren't necessarily the route to better overall picture quality. Check the next page to see how the D40 compares against the D80 and Canon 400D / XTi in our outdoor real-life noise tests.