There's a good deal more resolution on tap here than with the Canon EOS 1100D, as the Canon EOS 550D boasts an 18MP sensor that matches far more advanced cameras in Canon's line-up, like the Canon EOS 60D and Canon EOS 7D.
As with other current Canon DSLRs, iFCL metering is extremely accurate, taking colour and luminance information into account, as well as the focus setting. However, the Nikon cameras also do this, so it's not something that's exclusive to Canon.
What we have noticed is that the Canon DSLRs tend to bias exposure settings much more to the light and colour levels at the active focus point, so you need to be more careful that the active AF point doesn't line up with a particularly light or dark region in the frame.
The memory buffer of the Canon EOS 550D and Canon EOS 600D is a little larger than that of the Canon EOS 1100D, and is able to hold six 18MP raw files instead of just five 12.2MP raw files.
It seems rather strange that Canon's specifications suggest that the Canon EOS 1100D can shoot 830 JPEG images in continuous drive mode before slowing down, whereas the Canon EOS 550D and Canon EOS 600D are only rated at 34 JPEGs.
In our tests, with a fast memory card, none of the Canon cameras featured in this group suffered a slowdown in long sequences of around 100 JPEG shots.
Textured grip areas make for much more assured handheld shooting compared to the 1100D, and image review is aided by an LCD screen that's of far higher resolution and is much less reflective. The 3.7fps maximum drive rate is a step up from the 1100D, but still not quite as quick as the 4fps of the Nikon D3200 and D5100 models.
As with both of the other Canon cameras in this test, images don't tend to look as punchy and vibrant as the ones taken by the Nikon cameras. In addition to this, the Auto Lighting Optimizer is more prone to reducing apparent contrast in pictures, especially when compared with Nikon's Active D-Lighting system.
Images aren't quite as bright as with the Canon EOS 1100D, but they still lack the vibrant punch achieved by the Nikon cameras on test.
Despite having the same 18MP sensor as the Canon EOS 600D, the Canon EOS 550D scores poorly for resolution, coming joint bottom with the Canon EOS 1100D.
Image noise at high ISO settings is much more pronounced than with the Canon EOS 1100D, or the Nikon D3100 and Nikon D5100.
Typical of Canon cameras, colour quality is very true to life. Retention of saturation in highlights is better than with the Canon EOS 1100D.
Image test verdict
Image quality is very natural but, as with the Canon EOS 600D, Canon's Auto Lighting Optimizer can sometimes drain contrast from scenes.