Your camera and lens may be weather sealed but it really cannot take a downpour for too long or too often. If you don’t want to let the weather take away your shooting fun, or you have to shoot in any weather for a living, you need to get a rain cover to protect your gear.
I found there are many names for similar items : rain cover, rain cape, rain sleeve/rainsleeve, elements cover, camera cover, etc. Rain cover seems to be the most popular name. The prices also vary greatly, from $200+ to 7 bucks . The most expensive ones are made by AquaTech, less expensive ones by Tenba, OP/Tech, Lightware, Kata , and others. The choice should really depend on what you need based on your camera/lens combination and the type of shooting. The least expensive one may work for you just fine. However nothing should prevent you from making a fashion statement with the most expensive one if you can afford it.
For the budget-conscious types, here is the DIY rain cover tip: Find a clear plastic bag, cut a hole in the bag at an appropriate location, attach it to the lens hood using duct type.
Keywords: element cover, Photo accessory, rain cover, rain sleeve