While I was visiting the Minister's Treehouse in Crossville, TN two weeks ago me and my Filson bag encountered a pretty serious rainstorm that just would not let up. I snapped a few pictures of it's exterior right before jumping in my car to escape the wetness. The bag performed extremely well in these conditions....I detected not a drop of moisture in the interior of the bag where my cameras were. I had even set the bag on the ground a number of times without any extreme absorption, which was a joy to see. I do have to point out the problematic design of the exterior pocket on the Photographer's Backpack (last photo). The structure of the pocket leaves it open to the elements on each end, allowing water to freely enter. I have to think Filson understands this because there are two brass eyelets at the bottom of the pocket, maybe to drain water or vent moisture. It's not a problem to keep sensitive equipment in other secure parts of the bag, but I have to wonder what a person would keep in there happy to have it get soaking wet. If the flap was just slightly larger, any water would be diverted. See my more exhaustive review of the Filson Photographers Backpack here.