Congratulations on investing in a camera that's well suited to your task!
You're only going to have to compromise on one criteria - no zoom.
Once you see the quality of photos coming out you won't mind so much.
I've been spending quite a bit of time on this topic lately - not only with my own equipment, but also borrowing other equipment.
Here's the story.
Pentax is not optimized for sports, yet many Pentaxians have managed to get good shots with one. Pentax realized their weakness in AF performance and have made significant strides in the last couple of generations, with the K-3 being the best. Like I said - good choice! Here are two threads you may have seen on sports photography using Pentax:
https://www.pentaxforums.com/forums/115-pentax-k-5/115277-k-5-sports-photography-112.html https://www.pentaxforums.com/forums/172-pentax-k-3/242969-sports-images-k-3-a.html
My images are here:
EventTime Photos
Contrary to most (if not all) other brands you'll actually get better AF performance on your K-3 if you buy a screw-drive lens. The only lenses with in-lens motors fast enough to consider are the DA*300/4, Sigma 70-200/2.8 OS HSM (latest version only), and
possibly the DA*60-250/4. I've used the first two recently, and while AF performance wasn't up to my screw-drive lenses (even on a K-5 IIs), they were usable for sports. The most prominent guy I know of who was using the DA*60-250 for sports was Ron Hendricks, and it worked OK, but he gave up on it and is using the DA*300. He told me he
believed the screw-drive *300 lenses focused even faster than his DA*300, and when I compared them directly this turned out to be true.
I think you have 5 possible good options here in screw-drive. You should use one or more to take advantage of the way your K-3's been optimized:
- DA55-300 (any version) - definitely won't give you the IQ of the other 4, but will still give you some good shots and may focus fast enough. It's economical.
- Tamron 70-200/2.8 - much cheaper than the Sigma. I haven't had a chance for hands-on with one yet, but from what others have said about it on current bodies - combined with my experience - I believe it will also focus as fast or faster than the Sigma on a K-3. Most Pentaxians don't buy both lenses plus a new K-3 (in order to directly compare them), so they're relying on older information. But Tamron owners with newer bodies are happy with the AF performance.
- Pentax F or FA135/2.8. Fairly economical, very small, fast focusing, high IQ. One of my favorites.
- Pentax FA*200. Optically identical design to the DA*200, which I owned for about 2 weeks. IQ on the DA*200 was nice, but the SDM AF speed was
horribly slow for fast moving sports. However, the screw-drive FA*200 should be the best of both worlds.
- Pentax F* or FA* 300. I got noticeably better focusing performance with the F*300 than the DA*300 indoors in a gym last weekend. I also think the IQ is
slightly better on the F* and FA*, and the F* has a built-in hood. But make sure your F* is a good copy, because only some of the spare parts are still available. If you'd rather not have to cover your lens up in the rain you can get away with the DA*300, but you will miss more shots due to focus issues.
A long shot that might work well here is the economical Tokina 80-200/2.8, but I don't know of anyone using it for sports on a current body, so we're not really sure.