You asked
Is the pentax hd d fa 70 200mm f 2 8 ed dc aw good for sports?
Here is what the site says about that.
From Pentax HD D FA* 70-200mm f/2.8 ED DC AW: Pentax HD D FA* 70-200mm f/2.8 ED DC AW: A zoom lens by Pentax for Full frame cameras, 70-200mm f/2.8. Specs - Maker: Pentax - Focal length: 70-200mm (zoom) - Maximum aperture: f/2.8 - Made for: Full frame sensors - Mounts: Pentax K - Stabilised: no - Autofocus: yes What it frames like - On full frame (Pentax K): as marked, 70-200mm. - On APS-C (Pentax K): like 105-300mm on full frame; f/2.8 gives about the depth of field ...
From Wildlife and sport: Reach: Focal length is the first thing to sort out. - Sport from the sideline and larger animals: 70-200mm to 100-400mm on full frame. - Birds: 600mm full-frame equivalent and beyond. Birds are small and far away; a common saying is that you never have enough reach for them. Smaller sensors help here. A 100-400mm lens on APS-C gives the view of about 150-600mm on full frame, and on Micro Four ...
Quoted from this site's pages.