The Tamron 17-50/2.8 Di II VC is a viable alternative to the Canon EF-S 17-55 f/2.8 IS USM, $1060 (review) at a price that’s about $450 lower. The image stabilization is very effective and overall performance is good, though not quite as good as the Canon lens, especially wide open and at the edges of the frame.

Canon's EOS 550D / Rebel T2i continues the company's tradition of filtering-down features from a higher-end model into a more affordable body. As such, the 550D / T2i enjoys the same high resolution photos and flexible movie modes of the 7D, not to mention its sophisticated metering system, and there's even a brand new 3:2 shaped screen which is a perfect fit for stills in playback or Live View.

Being a 50mm with a maximum aperture of f1.2 this lens has plenty of background blur but more importantly the bokeh or the quality of that background blur is excellent. One of the reasons you want to be buying this lens is for its bokeh. It is creamy, buttery, smooth and out of focus highlights at f1.2 are elliptical while at smaller apertures they turn into lovely eight point stars.

The Canon EOS 1D Mark IV is delivering a higher percentage of in-focus AI-Servo shots than any DSLR I've used to date. No, it is not perfect (I don't know if perfection can be achieved with a human behind the viewfinder), but, at 10fps, it delivers a VERY impressive number of sharp shots from a burst. For example, in the 21-shot sequence shown below in this review, only 2 or 3 shots are even slightly out of focus - and even these are very close.

the EF-S 18-135mm IS performs well for the price, but don't expect miracles. Like all lenses with long optical ranges, it suffers from quite noticeable geometric distortion and vignetting (although the latter can be effectively corrected using software or in-camera on recent bodies), and the corners are also soft at larger apertures.