Think Tank Photo エマージェンシーレインカバー（ラージ）

It’s barely larger than a folded map, so I just toss it in the bottom of my bag and forget about it until the sky opens up. Last week it handled a solid half-hour of pouring rain on a trail shoot and my camera stayed bone dry the entire time. You can’t beat that for the price.

I was skeptical about such a lightweight cover, but it unrolled easily and fit my 70-200mm lens setup perfectly when that sudden storm hit. The velcro closure kept everything dry while I hiked for another hour in the rain.

Folded up in my bag it takes almost no space, but when that surprise downpour hit on the trail, it slipped over my kit in seconds and kept everything bone dry. The simple pull-over design is exactly what you want in an emergency.