Here's a simple design I thought of recently while I was out hiking with my son.
My goal was to make an UltraLight Camera Case that would double as a shoulder pouch. This will keep the camera protected from the elements and within easy reach at all times so I don't miss any photo ops.
The material I chose is a super tough 1.43oz (per square yard) cuben fiber that I purchased from ZPacks. I'm a bit addicted to this stuff right now because it's so durable and lightweight. It's the same material I used to make my backpack about 15 months ago, and it has held up beautifully. I angled the top enclosure, making the front lower when attached to the shoulder strap. This makes it easier to get your camera in and out without fuss, and also helps to shape the front when it's open. The taller back is necessary to form a rain proof closure...
I used 1.25mm shock cord instead of a normal drawcord, with no cord lock. This makes it easy to open and close with one hand while hiking. To close, simply pull the shock cord over the front and around the back of the camera, which folds the top opening down making the case rainproof. I sealed the seams with clear silicone to ensure it's water tight.
When not in shoulder pouch mode, it works just as well as a stand alone case. I'll store it like this on my tent floor at night.
I've been trying to think of the right design for quite a while, and I think I've got it pretty close. Oh yeah, I almost forgot...it weighs only 0.10oz!