Originally posted by liukaitc OH MAN!!
I tried my friends d7000 with nikon 17-55 f2.8.
The auto focus in low light is way way better than my k-5 with 16-50.
It is just so precise, fast, hardly hunt.
At that moment I really want switch to d7000....
One thing is that the focus assist light light on much often than k-5's which I think helps focus a lot and is more powerful than k-5's.
but in day light, I think not much difference between two.
Even my Sony HX5 focus's very fast in good light - it's when we need the camera to perform in less than ideal situations with ideal outcomes, this is where the difference comes in and why paid sport togs will use a D3s or Mkiv for it's af superiority in low light.
As mentioned earlier I needed a dslr that could give me a definable constant result using af in low light and when using flash - I simply couldn't take the risk with the K5.
Also Nikon zoom lenses just focus far faster in inclement light than anything similar from Pentax.
3D tracking is (which Pentax do not have to my knowledge) is incredibly accurate and extremely helpful in a lot of situations.
I own the consumer Pentax 55-300 and the Nikon 70-300 VR - it simply is no contest with re af speed, lock on and generally lens build
The other day I took out my K10D and put the 55-300 on it (it's still a very sharp lens) but it just felt archaic after using the 70-300 for just on two years
I do have a mate who is one of those guys who "will never leave Pentax over his dead body" types and he bought the K5 but has given up on covering indoor climbing comps and such