Should be no problem. I haven't tried it with my K10 (I gave it to my son to use) but it should work fine. The bigger concern you should have is what lens are you using it with. If contrast and lighting is good it seems to work with even my slow lenses. But it truly excells with a fast lens of mine - Tamron 28-75 2.8, even when it is stopped down far beyond 4.0. I believe that is because most fast lenses are also a higher contrast lens.
I have a Sigma 150-500 telephoto