Originally posted by windjammer The lens I ordered is a "DA 55-300mm F4-5.8 ED". I also ordered the "DA 18-135mm F3.5-5.6 AL IF (DC) WR" for a walking around and rainy day lens.
Those are not great low light sport lenses. They are nice for reach, but the aperture is too small for good low light performance. Thankfully the K5 lets you crank up the ISO and get fairly clean images because you are going to have to shoot at 3200 or 6400 most probably to be able to get any sort of shutter speed necessary for sports.
You really need a 2.8 or larger aperture lense. The 50-135 2.8 would be good, or other similar third party, or even a prime some where in the 70mm to 135mm range with a large aperture would be way more suited than the lenses you have.
Your lenses are great walking around in broad daylight lenses, but just not cut out for night time sport shooting.
Also, not sure if you understand on the lenses you do have the aperture is variable. At the long end of the zooms it's the larger number so you only get the F4 and F3.5 if you don't zoom very much at all. As soon as you start zooming, you lose aperature size until you reach the end of the zoom range and hit F5.8 and F5.6.