Sure, you can repurpose any sack into a camera bag. We doubt it will give you the best experience, though. The Ultimate Photographers Bag, on the other hand, is specifically fashioned for lensmen on the go, making space for both your fancy equipment and all the other gear you need for regular living.
Made by Inside Line Equipment (ILE), the special-purpose rucksack came about after an exchange of ideas from urban cycling blogger John Watson and a designer from the group. The final result is a sleek-looking backpack with all the pockets and compartments your friendly neighborhood DSLR-toting enthusiast can ask for.
The ILE Ultimate Photographers Bag is a handmade sack that measures 13 x 22 x 8 inches. It has two main waterproof compartments -- one with a rolltop closure on the upper length (to hold food, tools and other gear) and a buckled plus zippered camera compartment with dividers at the bottom (can hold an SLR body, a pair of lenses and a flash). There's a pocket on the upper compartment for laptops or tablets up to 17 inches, large side pockets for tripods and light stands, and compression straps.
Body is made from 1000D Cordura, with the bottom clad in Ballistic Nylon. For comfortable handling, it features a padded back, padded shoulder straps, and adjustable straps for cinching to your waist and sternum.
And in case it matters to you, the ILE Ultimate Photographers Bag isn't some sack that factories are mass-producing in China, either. Instead, each unit is handmade out in California. It's built to order, though (seven days turnaround), priced at $360.