I'm looking for a lens case that will fit the new Tamron 150-600mm with the tripod collar mounted and the hood reversed. B&H's website recommends the Lowepro 13x32cm LP36307, which has interior dimensions of 5.1x5.1x12.6 inches. However, my tape measure says the lens measures 11" long and about 6" wide, factoring in the collar and lens hood. The lens may fit in that Lowepro, but I'd have to take the collar off.
What I'm doing for storage right now is wrapping the lens in a sheet of those air pouches used in shipping, and putting it in a tool bag. The air pouches offer some cushioning and fill in the empty space in the bag so the lens doesn't bounce around.
It works, but the tool bag takes up more space than an actual lens case would. I'm finding cases that are long enough, but not wide enough for storage with the collar on. Does anyone have a recommendation for a lens case?