This is one of the cheapest L series lenses that Canon has in its lineup- a snip at about £500. The L classification that Canon uses is for its Pro set of lenses- these are for the professionals and are build for that purpose. With a UV filter on the end, this lens is weather sealed, which means it should be able to put up with anything that is thrown at it. Can be used on full frame cameras like the 5d (&mark2) and 1d series, which means the wide 17mm means its perfect for landscape photographers. On the other hand, if this is used with a crop sensor body (the xxD or xxxD series) then this will make the lens a 27mm - 64mm. Not so useful for the landscape ...  Read the complete review

You expect a good quality lens from a quality manufacturer such as Canon to be of exceptional quality and I have always found this to be the case. The Canon EF 17-40mm f/4L USM certainly doesn't let the side down. I purchased this lens a while back now to use with my Canon 400D and I have been really pleased with its performance. The 17- 40mm is probably one of the most popular lenses in the Canon line but at over £500 it is a bit on the expensive side and so might be a bit too ambitious a move for many people although you might pick up a good second hand one for less than £450. Nevertheless, for the price you still get a very well built lens that takes excellent ...  Read the complete review