Think Tank Photo Lens Changer 75 Pop Down V3.0 (Schwarz)

I can slide my 70-200mm f/2.8 into this with the hood reversed and still have room to pop it down to shooting position without fumbling. The padding feels sturdy enough for tossing in my backpack on a hike.

Finally, a case that lets me carry the 70-200 attached to the body with the hood reversed, saving so much time switching lenses in the field. The pop-down feature gives just enough extra length to fit the hood in shooting position too, which is perfect for quick access.

The padded interior is snug enough that my 70–200mm f/2.8 doesn't shift around, but the pop-down section gives me just enough room to leave the hood reversed without a fight. I've thrown it in a backpack a few times and the shape holds up well.