Ken, my waist pack is 2L. It just barely fits my camera and lens, plus an extra lens with a hood, and an extra battery. (Side note, I'm digging m4/3 for hiking!). Its small enough that it doesn't bounce much and doesn't block my view of my feet like my previous chestpack for my DSLR did. I'm of the opinion that the smaller, the better when it comes to supplemental chest/waist packs.