here is another example, as the k-5 can accept underexposures ( at 100iso) you just have to expose the sky and clouds correctly, forget about the real scene ( here a castle) and hope there is not too much stops beetween sky and scene.
then in LR use fill light, iso, brightness , black level to setup a correct image (you can make it from nice to HDR
)
Please no artistic consideration about this pics, it's only to show how dark the raw footage can look like and what you can finally get
( the first is the raw directly convrted to jpeg in LR, the second is corrected ( and yes i've also removed the birds=black dots in the raw).
And it's not symmetrical:means you can't overexpose sky and get it back in PP.