10. Image Quality and Megapixels

Colorimetry A camera’s colorimetry is fundamental to the quality of the final results. Since these cameras are aimed mostly at amateurs, we used automatic color balance in running this test. The Nikon D60 came very close to neutrality, delivering faithful images with good color saturation. As on other Canon cameras, the images the 450D produced are saturated and slightly warm by default in order to give neophytes’ photos a slightly flattering effect. The α350’s pictures are also of good quality and are fairly neutral, with a saturation level that is a little high for our tastes. Finally, the K200D’s colorimetry is warm and pleasant, but comes close to being overly flattering.

Management of low light The last fundamental factor for evaluating a camera’s quality is how it manages noise in low light. Here we’re on Canon’s home territory. And indeed, of the four cameras we tested, it produced the best quality when light was low (in particular thanks to its CMOS technology and its sampling RAW files at 14 bits).

The loss of quality as a function of sensitivity was regular, and the manufacturer hasn’t compensated for possible shortcomings by using a high level of accentuation or smoothing, even when the grain-reduction mode is active. By the way, that mode is so effective that anybody but users of burst mode – which slows it down a lot – should keep it enabled all the time.

The assessment is about the same for the Nikon D60, except that a little more mottling can be detected at high sensitivity settings, despite the lower definition for the same sensor size. At an identical size, the sensor with the lower definition is generally the one that performs better in low light. That is not the case here, which is a sign of the quality of the 450 D’s management of low sensitivity settings. We should also note that noise reduction on the D60 can only be enabled starting at 1600 ISO.

With the K200D, however, you can see the first significant loss of quality between 400 and 800 ISO. At that sensitivity, the images are still fully usable, but the difference with the Canon and Nikon is already perceptible. At 1600 ISO, digital grain is fairly well managed, but mottling becomes a problem.

The α350 is behind its competitors when it comes to managing low light. Noise is relatively well contained, but from 400 ISO, mottling becomes visible. It increases again at 800 ISO and becomes a real problem at 1600 ISO. The maximum sensitivity setting, 3200 ISO, shouldn’t be used unless you really need it. Given its high definition (14 million pixels), the α350 isn’t that far behind, but it did turn in the worst performance of the cameras we tested.

The Importance of Definition The Sony α350 has the highest resolution, with 14 million pixels. But the only advantage of such high definition is the ability to make large-size prints. The difference in definition between the cameras (10 MP for the D60 and K200D and 12 MP for the 450D) isn’t negligible, of course. But it needs to be put into perspective.

With 10 million pixels you can make A3 (11x17) prints with no problem, but amateurs rarely make prints that big. Also, it’s better to slightly “blow up” a good image artificially using interpolation than to have an image with high definition that might show problems like excessive grain.