In the past, I’d used Lowe Pro Photo Tracker AW backpack. It is a good bag, but these days I have a lot more gears to carry. Nowadays I often use a smaller Lowe Pro fanny bag for a shorter lens with other accessories.
I was introduced to Think Tank Company in 2007, which claims to make a bag “by photographers for photographers.” So far I found most of their bags extremely well-designed and well thought-out.
The Think Tank Airport Security roller bag is big enough to fit my 600mm f/4 or 500mm f/4 (even 800mm f/5.6), two camera bodies, several other lenses and accessories, such as flash, extra batteries, battery pack, etc. This bag is so deep that I can fit both my EF 70-200mm f/2.8 and EF 180mm f/3.5 macro lenses straight down. Moreover, my Mac Book Pro 15 inches laptop fits well in the stretchable front pocket.
The Think Tank Airport Security also comes with a backpack strap, but I won’t recommend anyone to use that, considering its size and weight.
The bag has combination locks and cables, so I can safely leave this bag locked inside my vehicle (most of time). The way I do it is to wire the cable around the vehicle frame and lock it with a combination lock (TSA lock).
The quality of the bag is a first class material and guarantee for life unconditional. I won’t hesitate to recommend this bag to anyone. In fact, many photographers who I introduced it to now love it too.