I just added some more OP/TECH gear to my 2 regular pro loop straps to attach the camera to a backpack.
The uni-loop connectors (#4) are attached to the Lowepro Vertex 300 AW
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The camera can be attached directly to the backpack which looks like this:
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This gives a very good balance especially when using heavy equipment.
In addition to that I got the pro-loop system connectors (#4) XL because the regular ones are a bit short for the 300/2.8 (straps are directly attached to the lens so the camera is closer to you than normal)
