In my younger days, I'd pack my backpack as if for any 10 or 11 day backpack trip, and toss the 4x5, film, 5 holders, changing bag, tripod (Gitzo 300 - pre carbon fiber days), meter, etc on top of everything else. I had the largest volume pack Gregory made. Okay, it weighed 85+ pounds, but like I said, it was my younger days! I like to keep it at around a pound a year now -- up to about 60 pounds for a week...I am at 250 pounds (aiming at 230).