For the 35 and 2 1/4 try large Ziploc bags, a cable release and a lens shade when out in light rain. They are clear and flexible and you can zip them closed to the lens shade. I'm not sure it would work with the 4x5. Perhaps a folding umbrella will help. Wipe the equipment before putting it away in the camera bags. Two years ago it rained 8 days out of a two week trip to New Zealand and that's how I handled my 2 1/4 with no problems including cutting a slit in the Ziplocs so I could attach the cameras to a tripod.