How do you keep dew off wide angle lenses?

[rogerg]

Interested in solutions to this problem. Lenses such as 17-40mm, even 50mm.

This range of lenses are too wide to have significant dew shields extending out from them, and needing to use the manual focusing ring for focus adjustments limits where you can place a dew strap on the lens body.

Thanks,
Roger.

[MrB]

Maybe a very small hot air blower... low heat low flow sort of thing. Not sure what effect, if any, it will have on the image though?