I've had my Canon 30d for a bit now, and have fallen in love with it :hail:. When I picked it up, I also grabbed a Tamron 17-50mm f/2.8, since Ilove landscapes. A damn fine lens, too! Now my next issue is that I'm in need of a telephoto zoom lens, preferably something that hits ~400 range. Something suitable for almost everything from Photographing the local airshow, to wildlife, and just about everything in between. Now, the following is what I understand some of my options are; Sigma 50-500mm f/4-6.3 EX DG HSM (Aka. 'Bigma') - The ultimate jack of all trades. I'm tending to look seriously into this lens since it would mean complete coverage from 17-500 with just two lenses! Of course, Sigma's *coughs* 'commitment to quality' can make picking up a bigma a hit or miss. The full time manual autofocus is also a big plus! Canon 100-400l f/4.5-5.6 IS USM - It's a very popular lens, and the IS is a definate bonus if you hand hold it... but then again, I rather doubt my ability to handhold a shot that's 300+, so any long distance shooting will be done on a tripod. It's also an L, and I must admit, I'd like at least one white lens.... Expensive though, and would leave a 50-100mm hole in coverage, as well as delaying purchase of the lens for at least two months while I go through 'fund aquisition' to afford it . The local camera shop guy reccomends this lens, but I'm inclined to belive he just wants the commision. Tamron AF 200-500 f/5-6.3 Di LD (IF) - I don't know much about this lens, but it seems a comparable offering from tamron. The rather hight starting zoom range leaves a bigger gap in my coverage than the canon, but it also has a longer zoom than the canon. Of course, these three are only the ones I've looked at so far, and I'd be more than willing to look at any lens reccomended! So, any reccomendations?