The FirstLight 30L holds a substantial pro DSLR outfit including a 500/f4. FirstLight backpacks have a superior 11-point adjustable harness designed to fit most body shapes, and offer all-day comfort when carrying a substantial amount of photo gear. Lightweight but rigid, they give great protection to contents, using high-density closed cell foam dividers, and include a waterproof cover which doubles as a groundsheet. Thoughtful design features which will appeal to the active photographer include a dedicated pocket for hydration reservoir, stuff pockets for gloves, hat etc, water bottle pocket, built-in whistle in the sternum strap etc. Sized to suit most airline carry-on requirements, they have grab handles on two sides to make stowing them in an overhead locker a cinch.