Collie lover wrote:
I'm looking for something that I can attach to my camera bag. it's a Think Tank with a waist pack that pivots. I'd like to be able to carry my large lens attached to "rails" on the waist pack. May see if I can sew a strip of webbing onto the lens case so I can run the strap of the waist pack through it. If not, I'll see if I can make something with a draw string, padding and a strap for attaching to my waist pack.
Collie, Lowpro makes a belt system that is made to attach those lens cases to. The cases will also attach to some/most(?) of their backbacks.
I think the belt is called a Lightbelt but they may have several. Good luck. ;-)