Owner contribution
When selecting a bag, the main points for me where that I could fit my 40D with a 70-200 f/4 mounted (or similar size lens), be able to get to the camera fairly quickly (sling and/or at side) and to compact ie. Not have tons of extra pockets which I wouldn't use. The Tamrac Velocity 8x seamed the prefer choice. As you can see the main chamber is fairly deep, with 2 channels either side. On each side you can either stack 2 smaller lenses (like an 18-55 IS) or one large lens like the 70-200 f/4. The main chamber will hold a 40D with a 70-200 f/4 mounted, shown here: . In the main chamber you could also put a smaller lens at the very bottom, then put a lens like 60mm Marco mounted to a 40D above it, show here:
What works
Well made, compact (less wasteful pockets), big enough to carry 4 smaller lens (or 2 large lenses) and also 1 large lens mounted, fairly cheap, well padded shoulder arm, completely removable inserts
Room for improvement
harder to find, limited choice of colours
