Lowepro DryZone Large Camera Bag Backpack DZ 100 Black.
I've used it on many trips over 10 years and it performed excellently. The Waterproof zipper does not seal anymore, so it is NOT FULLY WATERPROOF. It is excellently water resistant still: and in most of my trips I did not close the waterproof zipper but my gear stayed dry. It has an outer rubberized part and an inner vinyl and padding section which zips closed separately and keeps your gear cushioned and protected. The inner section has velcro dividers and can be configured for whatever gear you have that trip.
There is additional storage in the outside soft cover which can expand to hold a lot of gear plus a tripod holder on the outside. Plus it fits under seats on airlines!
My days of crazy trekking through the jungle are over, so this can serve someone younger now!