Every photographer wants his or her images to be as sharp and noise-free as possible. Software based noise reduction such as Noise Ninja or even the noise reduction settings in Adobe Lightroom 2 can help tremendously but preventing noise “in camera” makes all the difference in the world.
The Canon 40D includes a custom function for high ISO noise reduction which is enabled by selecting C.Fn II:Image -2 and setting it to 1 (On). According to Canon:
“The EOS 40D features a custom function for high ISO noise reduction. This can be used on images shot at high ISO speeds to help reduce the appearance of noise in the final image. If the custom function is turned on, some noise reduction will be applied at all speeds, but it will be most effective at higher ISO settings. If you do set high ISO noise speed reduction, you will notice that the burst rate is dramatically reduced due to the extra processing required in the camera. In the EOS 40D, the maximum burst will only be 8 shots regardless of the file size recorded.”