Compared to Nikon D5000 & Sony A55
The EOS 600D uses the same 18-megapixel sensor already seen in the EOS 550D. This sensor has a higher definition than that of its competitors, and largely dominates the D5000 (only 12 megapixels). Back in the days when the D5000 was launched, this was a good standard. But more pixels does not mean better metrics, and indeed, the DxOMark Scores for the EOS 600D place it behind both the D5000 and Alpha 55, handicapped by a lower Landscape and low light performance scores. The D5000 and the Alpha 55 have comparable DXOMark Scores.
The Canon is deeply penalized by persistent noise noticeable in the dark areas at low ISO settings. The dynamic range graph and the EOS 600D curve directly points to this phenomenon. From ISO 100 to ISO 400, the EOS 600D’s curve is horizontal, with both the D5000 and the Alpha 55 scoring 1EV above it.
Once again, as noticed with the EOS 1100D, analyzing the full SNR graph for the D600 confirms the problem. The curves representing ISO 100 and ISO 200 overlap on their left sides (the dark zones, with the curve for ISO 400 very close as well, which should not be the case.
Let’s look at the SNR 18% metrics, which simply confirm all of this: the D5000 produces less noise than the EOS 600D, no matter the ISO speed. The difference is as high as 3 dB between ISO 100 and ISO 400, and slowly decreases afterwards.
The same kind of performance can be noticed for color sensitivity. The EOS 600D is outperformed by the D5000, and here again the difference can be quite significant, reaching almost 3 bits at ISO 400.