Alright guys my trip is quickly approaching, and while I should probably be more worried about booking things like rail passes and hostels, I'm focusing on what camera lenses should accompany me and my 40D :-D

I've already settled on a 17-50 F/2.8 Tamron for shorter pictures but still need something for telephoto. Nearly everything on this trip will be hand held (I think I've decided against a tripod) so something with IS would be lovely, but not a necessity. I want the best bang for the buck and with that said my price limit will be somewhere around $750 for a single telephoto lens - but then again I could always purchase a very nice L series used and just sell it when I return... who knows.

I've been looking at a Canon 70-300 IS USM to couple with my Tamron, but honestly I'm not that knowledgeable when it comes to telephoto lenses. Any and all suggestions are welcome. We will be traveling quite literally all over the continent so shooting will range from low-light situations inside cathedrals and castles to the bright snow of the Swiss Alps... close up portraits to landscape shots.

Try to keep in mind that everything being taken with me on this trip will need to fit into a 55liter backpack. Myself and a buddy will be hosteling it up across Europe, so lugging around a steel case for the camera body and lenses isn't an option. Size does matter!! Albeit not in the traditional manner :-P

Hello Lenny,
I was in Europe last summer (Germany, Venice, Prague, etc...) I used a 5D and 24-105L IS. I brought other gear, but the 24-105L was used for 95% of my work... I sold the lens after my trip as I am a nature photographer,... but I now really miss it! For general photography, I think the 24-105L is a super optic.

As for a longer lens, I also brought the original 70-200 f4L. While this lens does not have IS, it is fairly light and is one of Canons best performing zooms at any price.
have fun during your travels,
bruce

In your price range, you're looking at probably the right lens for your trip. I have one that I keep for the sole purpose of lightweight hiking. It really doesn't get much use, but it's nice to have that option around. The current 70-300 IS is a nice sharp lens. The older versions aren't known for their quality optics. Another option, albeit more expensive, may be the 70-300 DO. If price wasn't that much of an issue I might suggest the 70-200L IS f/4. It's a bit bigger/heavier but reportedly one of the sharpest Canon lenses in it's class.

The Canon 70-300 IS that you mentioned is probably a good choice. It takes very nice pictures, is within your budget, and is "travel-sized". It is also less likely to draw attention than the white Canon L's, like the previously mentioned 70-200 f4L.

I think the 70-300 is your best choice given your budget and lack of tripod. I have been here in Europe for the last two and a half months and about 97% of my pictures according to lightroom have been taken with my 17-50. Keep that in mind.

Didn't I just read this thread? Oh yeah, I did: http://www.fredmiranda.com/forum/topic/625761/0

Next thing you know someone will bring up the 1200. Oops.... too late.