Going to Alaska this fall for a 7 day hike in Lake Clark National Park. My main pack is an Osprey Aether 85. Unfortunately it's the original model from 2006 so it doesn't have the built in convertible day pack. I plan to do most of my overnight hiking the first 3, maybe 4 days. After that i'll be staying at one spot at night and doing day hikes out from there.

So i'd like to find a daypack that when not being used takes up minimal space and weight. I suspect my day hike items might include:first aid kit, water bottle, bear spray, GPS, binoculars, a snack or two. I don't want something super lite like a drawstring pack, but would like something with something somewhat decent for shoulder straps.

So lite gear experts, what do you suggest?