Ditto on ThinkTank. I use the TT International when carrying a 500mm + 2 pro bodies + lenses + flash, accessories, portable drives and 15" MBP, etc. A tip is to not use the Canon 500mm cap and get a Zeck lens cap instead (from naturescapes.net - saves space and easier to use in the field). Also consider getting the low profile 4th Gen lens collar foot, also from NS.
|Fangorn Forest by cand1d|
|Yosemite Falls with Moonbow by Jonathan Shapiro|
from Best Landscape of the Week 4