Jacob Fox wrote a review of Mountainsmith Descent AT Chest Pack on June 18, 2011
I bought this as I could find no decent alternative to photographing while backpacking (with my pack already full of non-photo gear.) I am able to fit my Lumix G1 with 45-200mm lens and full lens hood attached, secondary lens, and Canon Vixia HF S200 video camera with lens hood attached all in the main compartment. Plenty of room to store other small accessories and the built-in raincover is a must for backpacking. The cameras are easily accessible in front of me - the only concern I would express is that you need to be a bit more wary of your footing as the chest pack limits the view of the ground right in front of your feet! I haven't taken any spills but it's worth noting.