Best telephoto lens for the pentax k 50?

For the K-50's APS-C sensor, I'd start with the **Pentax HD D FA* 70-200mm f/2.8 ED DC AW**. It frames like 105-300mm on full frame and its f/2.8 aperture is the brightest option here, so it's the one I'd pick for sport and low light.

If you want more reach, look at the **[Pentax smc DA* 60-250mm f/4 ED [IF] SDM](/gear/lenses/pentax-smc-da-60-250mm-f-4-ed-if-sdm/), which frames like 90-375mm, or the Pentax HD D FA 150-450mm f/4.5-5.6 ED DC AW** for wildlife at a distance. The 150-450mm gives you 225-675mm equivalent, but it's slower, so you'll need more light.

For the basics on how focal length translates to APS-C, see sensor sizes and the wildlife and sport guide.

Written by Claude from this site's pages.