Hello all, I'm new to this fabulous forum but have come to you with a lens purchase dilemma.
I'm taking a two week vacation in Europe starting in May.
I shoot with a Canon 30D using a Tamron AF18-200mm F/3.5-6.3 XR Di-II. I'd like to buy a wide angle lens before the trip. Though, with an eye to the future, I plan to purchase the Canon 5D MarkIII when it comes on the market in a year or so. That being said, should I buy a wide angle EF lens that can fit the 30D now and the 5D later, or should I take the loss and buy an EF-S lens made for the 30D?
Common sense tells me to buy the Canon EF 17-40mm f/4L USM as it will be futureproof. The practical lens choice is to buy the Canon EF-S 10-22mm f/3.5-4.5 to complement the Tamron 18-200 I already have. The latter not being much of a choice as I'd rather buy the EF wide angle lens.
I suppose the real question is which EF wide angle lens would still do the job on the 30D and give me the wider angles that I crave? Do I even need to buy a new lens?(At 18mm the Tamron is not as sharp as it should be.) I'll end up shooting mostly landscapes/cityscapes (high and low light) with the obligatory family photo in between. Any advice or recommendations would be helpful in helping me learn more before making a lens choice.