First of all, the main compartment, which can be accessed by unzipping the back wall of the bag.. As camera bags usually do, this one includes a number of dividers that can be attached to the walls of the main compartment and to each other via Velcro. There are two long dividers that run from the top to the bottom of the compartment to divide the bag into thirds, and three short ones that can be used to subdivide the thirds. By adding a fourth divider from the camera bag that I'm retiring in favor of this one, I was able to give myself a 2x3 grid that accommodates the body of my D3300 (I have to unscrew the hand strap and drape it across other compartments), four lenses, and a lens ball. The different sizes of the various compartments' occupants tend to push against each other, and the connections of the various dividers can be a bit . . . imprecise, but it all seems to be good enough. Each piece of equipment is in there snugly enough that it won't be jostled but not so snugly that it can't be easily taken out.The final third of the compartment formed when I inserted the long dividers cannot be subdivided because the material on that side of the bag will not accept Velcro. The result is quite a large compartment which is only useful to me as an area where I can store miscellaneous accessories that can handle a bit of sliding around. I usually don't use a Speedlight, but if I did that would probably fit in this compartment quite easily. On the side of this wall are two very small Velcro chambers, each of which can just about hold one battery. (Quite convenient for me, since I carry three: one in the camera and two in reserve at any given time.)Up above all of this is a pair of pockets that can handle a few flat accessories, like my gray cards and a couple of cheap plastic filter wrenches that I've found it prudent to keep in my bag. These pockets are very loose and anything in them will certainly slide out if the bag is tilted.Behind these pockets is a separate compartment. The floor of this compartment is formed by another Velcro divider, so if you really wanted to you could remove that and access it while the main compartment is open; however, you'd have to disassemble so much that it can't possibly be worth the trouble. This separate compartment can be accessed via a zipper that only goes a short way down the side of the bag (further making it clear that this is intended to be treated as a separate compartment). With the exception of a key chain that can be snapped off of a strap, there is nothing in this compartment that would give any anchorage or stability to anything you might choose to keep in here. Nor is there any padding along the top and sides of the compartment. Thus, there's almost no piece of photography equipment I would trust in there. Which isn't really a problem, because everything I normally keep in my kit fits in the main compartment. Since I use my camera bag as my personal item when I fly, I anticipate using this space to store various small objects that don't need to be stored securely and that I might need to access on a plane or in a terminal. It will be a nice change from stuffing such things into my pockets. But otherwise I plan to keep this empty.The inner side of the bag's back flap, the part you unzip to access the main compartment, has a very large pocket designed to hold a laptop computer. Large as this pocket is, it's not large enough for my computer (which is fine; I very rarely travel with my computer these days). At least with the configuration of the camera bag that I'm using, I would be very worried that putting a computer in there would risk crushing it and/or some of the photography equipment. But it's hard for me to visualize someone else's computer in there.Zip the main compartment back up, flip a large flap over the top of the bag, and secure said flap in place with a pair of some sort of hook. These hooks seem to hold the flap in place securely enough, and are not too hard to unhook either, but I really don't see what advantage over a more conventional pair of buckles they're supposed to offer. Now that the bag is closed, I identify most of the areas for improvement. In addition to the perplexing hook closure, there seem to be quite a few extraneous straps; most can be easily removed, and the rest are unobtrusive enough. But whatever function they're supposed to serve is beyond me. There is a pair of looped straps at the base of the bag that can accommodate a tripod, and I certainly appreciate that. Before such a thing became commonplace on camera bags, I would have to carry my tripod separately whenever I needed it, and this was such a nuisance that I frequently just left it behind. There were plenty of occasions on which I'd come to a setting where a tripod would have been called for, and I had to pass up the shot instead.But aside from the tripod straps, and one pocket with an elastic cinch at the top to hold a water bottle, there's no opportunity to store anything on the outside of the bag. Not a single zipper pocket of any size, though there are plenty of places where such a thing would fit in nicely. It seems a waste. (What initially looks like a decently large zipper pocket is just a window into the main compartment of the camera bag, on the side without Velcro where I have my various accessories bouncing around. I don't think I'll ever need such quick access to that compartment; if ever there is a need to have something quick at hand, I'll store it in the separate zipper compartment instead.)Otherwise, the shoulder straps are adjustable across a huge range, so I think almost anyone will be able to find a comfortable length. I certainly have; and when I say I find it comfortable, that's as someone who hasn't worn a backpack more than a handful of times since I was in high school.Though I've found a few things to nitpick, the fact is that this bag holds all my photography equipment in a space that is compact but still roomier than a more conventional over-the-shoulder camera bag. It's comfortable and convenient to carry and I anticipate no real problems with it.The only thing I can't assess right now is how easily it will fit under the seat of an airplane. I don't anticipate any problems there but I will update this review if necessary the next time I fly.