Originally posted by HaWaIi50 If I want a good lens (not too expensive) to shoot during sports events, which one would you suggest me?
Something that's f:2.8 (or a little faster maybe) would be great; faster than 2.0 will be hard to focus. But your results at ISO 3200 look good. If you'd get an f:4 lens it'd be much easier to focus, and the shutter speed could be (6.3/4.0)^2 = 2.48 times faster.
The lens length depends on how close you can be and how tight a field of view you like.
The basic equation is:
Focal.Length.mm = Sensor.width.mm*(Scene.Distance/Scene.width)
The Pentax sensor width is about 24mm, so rounding up to 25mm for convenience,
Focal.length.mm ~ 25mm (distance/width)
or height in portrait orientation.
Say you'll be 40' from the Basket (mid-court front seat). If you want a portrait mode shot from the floor to the basket (10' off the ground) the focal length needed would be something like:
Focal.length ~ 25 *(40'/10') = 100mm
One of the best lenses available is the DA(L ) 55-300 zoom. It is F:4.5 at 200mm so would work well in your gym. The L version would cost you about $250, the non-L about $350.
Dave