Ok, Just for more clarity, I assume you mean that when in auto focus, you aim at the sky and do not get focus because the lens do not find anything to focus on, so it keeps trying to find something to focus on. That is normal. If you release the shutter and aim at something that it should be able to focus on, the lens should be able to attain focus. Can you perhaps tell us what settings you have regarding focus on your K-r, and what lens you are using? Perhaps somebody with more experience of the k-r or your specific lens, can give you some advise.