Originally posted by Michail_P Done that a ton of times. Works perfectly fine. I have invested a lot in quality general -use backpacking and my equipment never had any issues. Ergonomic design is very important. Always a breathing back and lots of pockets. Waterproof zipper is a great idea. I sometimes put some clothing (socks for instance) in it so the shakes are nearly gone.
I've bene an advocate of using a dedicated hiking backpack and a generic insert for a long time. But bag makers have adapted. Nowadays it's much easier to find true hiking backpacks, with good ergonomics, also designed from the ground up for photographers. With a non-camera bag the problem is always access to your gear. Dedicated camera bags address this.
Many bags now have adjustable lengths, load lifters, good hip straps, sometimes rigid frames, etc. They have nothing to be ashamed of when compared with non-photo bags.
For my part, since discovering the rotation180 bags from Mindshift gear, I've never hiked with anything else (and wouldn't, even if not bringing my camera).