The Hydrophobia 300-600 rain cover for DSLRs is now available from ThinkTank Photo for $150; the separate eyepiece is available for another $35.
It is designed to be pre-mounted on your equipment for quick deployment. When it appears it may rain, photographers attach the Hydrophobia over their lenses before going out into the field, rolling it up tight and out of the way. Then, when weather threatens, they simply unroll the rain cover over the rest of the lens and body, securely protecting both. The rain cover fits onto a 300 f2.8, 400 f2.8, 500 f4, and 600 f4, ideal for sports and nature photographers.
ThinkTank said the fabric used on the Hydrophobia is ten times as waterproof as normal fabric. Instead of a â€œsprayâ€ coating, a â€œfilmâ€ is applied to the underside of the fabric, as well as a tricot mesh to protect it, making it a far more impenetrable three-layer fabric. In addition a waterproof tape is applied to all seams, providing an even more waterproof barrier.