The EOS 1D MkIV is a relatively large and heavy camera. The integrated grip and high capacity battery significantly increase the size of the camera body when compared to an EOS 5D MkII and it's much bigger and heavier than something like a digital Rebel T2i. The 1D MkIV wouldn't fit either my LowePro Off Trail bag or my LowePro Mini-Trekker backpack. At just over 2.5lbs in weight it's also pretty heavy - and that weight doesn't include a lens!

This one's fairly straightforward: if you were looking, you probably were already thinking about getting this lens, and there's nothing to fault it. If absolutely need image stabilization and the sharpest, best image quality in a 70-200mm zoom, it's money well-spent. However, if you are less picky, you probably won't be disappointed with the tried-and-true original version of the 70-200mm f/2.8 IS, either.

The Canon EF-S 15-85/3.5-5.6 IS USM is measurably an improvement over the Canon EF-S 17-85mm f/4-5.6 IS USM, which it replaces. The image quality has been improved via the use of two additional aspheric elements and one UD element. This improvement is most noticeable at the edges and corners of the image at wide angle settings, where the image is sharper and shows lower levels of chromatic aberration.

There's little doubt that if we ignore the price then the Canon EF 50/1.2L USM is Canon's best 50mm lens. It's sharp, fast, well built, weathersealed and supports E-TTL II flash operation. The only question is one of value rather than cost. If you're a photographer who doesn't use a 50mm prime all that often, and when you do you tend to shoot at f2.8 or smaller apertures then you probably don't need the EF 50/1.2 USM.

Tamron seems to have had to make some sacrifices to add Vibration Control to its popular 17-50mm ƒ/2.8. It's not bad with regard to sharpness, just not as good as the non-VC version, leading potential buyers to decide how badly they need Vibration Control.