You must know that in principle, the greater the power of noise reduction, the greater loss in the data of the file. We, as photographers, always encounter occasions that we have to use high ISO to take photos in order to maintain a high shutter speed so that the image would not be blurred. Since the image was taken at high ISO, high degree of noise results, which greatly affect the quality of the photo. How to deal with such problems? There are a lot of ways to reduce noise by making use of computer programs. Different programs have different calculations in their noise reduction algorithms. Which way or which program should we choose?

A test was carried out on 4 Nov 2006 for the purpose of testing the noise reduction power of different programs.

Camera: Nikon D70
Lens: AF-S Nikkor 18-70mm 1:3.5-4.5G ED
Camera Setting: ISO 1600, F20, 1s, Centre-point Auto Focus, Auto Focus Assist Beam on, WB set to Tungsten, Camera set on Manfotto 055Pro Tripod with Manfrotto 410 Tripod Head.

Photo 1: RAW file from camera (without any treatment in noise reduction)
Photo 2: JPG file with noise reduction carried out by camera
Photo 3: 50% noise reduction carried out in the Raw plugin in Photoshop CS2
Photo 4: 100% noise reduction carried out in the Raw plugin in Photoshop CS2
Photo 5: 50% noise reduction carried out in Photoshop CS2 filter imported from the Raw file
Photo 6: 100% noise reduction carried out in Photoshop CS2 filter imported from the Raw file
Photo 7: Noise reduction carried out by Neatimage from the JPG file imported from the Raw file in Photoshop CS2
Photo 8: Noise reduction carried out by Noiseware from the JPG file imported from the Raw file in Photoshop CS2

Different crops were made in order to have a closer comparison of the photos.

Crop 1: 100% crop from the left-up corner
Crop 2: 100% crop from the left-bottom corner
Crop 3: 100% crop form the right-bottom corner
Crop 4: 100% crop at the television
Crop 5: 100% crop at the middle

Which way do you prefer to reduce noise? CS2 is good enough? Camera built-in JPG noise reduction is reliable? Raw is better than JPG? Noiseware is better than Neatimage in terms of noise reduction?

The judgment should be made by you. Welcome all comments.