Doug has a larger version of a Lowepro than I do. The one I have will cost you in US $ something from $45 to $60. This is the Nova Pro2AW, by Lowepro. The bag is essentially water resistant with a "goretex" or similar lining beneath the outside fabric. Mine has been drenched in rain and all inside is cumffy and dry. I would not immerse! It does keep the rain off. This one will hold two extra lenses and my D70 Nikon. The top has room for memeory cards, etc. The front pouch is fine for spare battery and lens hoods. The largest lens I store is a Sigma 18-120mm zoom. This bag and most will not hold the extra large lenses. I am very pleases with the bag. Note, I use a wide belt to strap with relative comfort around the waist and not the shoulder strap. Negatives are quick access. Photojournalists seem to use very loose bags with stuff rattling around and easy to get to for a quick lens change. I opted to protect the lenses and stuff and go for the "slow, determined changes". Works very well for me. If you can get an all-weather bag, do it. This does ease the tension when it suddenly starts to rain on you!