I have a Canon 7D and often take my camera on the road while traveling. In the past I've taken my Sigma 17-70 f/2.8-4 and my Canon 70-300 f/4-5.6, which means that I must switch out lenses quite a bit, depending on what I'm shooting. I get a much better overall image with the 70-300, but the 17-70 gets the big picture. Should I invest in a third lens for better travel portraits, close-up lenses to save space, or just a better lens overall (such as the Canon 24-105 f/4L)? I do love having low f stops for great focus and blur, but I also like having options, macro equipment, and reach. Perhaps there's no easy solution, but what would you do to travel relatively lightly in such a situation? Thanks!
Update (11/27/11): After many frustrations on past trips, I need to prioritize once more for a big trip, and your opinion could help!
I have a Canon 7D. I'll be taking:
A Canon 70-300 A Canon 50mm f/1.4 A wide angle--TBD
What wide angle should I purchase? I'll be putting it through heavy use (bumpy travel, dirt surroundings, 3rd world country environments, etc.), but don't have the money (or weight allowance) for an L-series lens. Currently I'm considering something such as the 15-85, though the 3.5 will be a bit of a challenge since I'll be shooting at night, too. What ONE lens would you recommend for this trip (as well as future use)? I'm absolutely open to used lenses or non-Canon lenses if there's a reliable source.