I've been hauling my 3 lens Hasselblad set in a Domke bag for awhile. Perfect fit and not too heavy. Then I added one more extension tube and one more lens. It still fit (barely), but dang is it heavy. I used to use an REI front loader backpack (like the Kelty Redwing) and various coolers and a fishing reel case for my 4x5 (cooler) and lenses (reel case)....so can I use my backpack for my Hasselblad kit? Well, I went to Cabelas today and found their Economy Advanced Anglers Travel Case. It fits my Hasselblad with lenses attached plus 3 more lenses, two extension tubes, a handful of rolls of film and my spot meter. The case is padded and has velcroed dividers that form ten compartments. I can put this into the backpack with room for a coat, lunch, water, etc. and still be reasonably easy to carry and access. I'll keep the Domke for times I don't need the extra lens, water, etc since it is easier to work out of, though. Maybe I can stop buying bags now?....(: