Best lenses for the Pentax K-3 Mark III
The K-3 Mark III uses the Pentax K mount with an APS-C sensor (1.5× crop). We picked the best lens in each category from 13 native lenses, plus a cheaper alternative where one is worth having.
Pair the K-3 Mark III with the Sigma 17-50mm f/2.8 EX DC OS HSM and add the Sigma 35mm f/1.4 DG HSM Art for low light and portraits. When you need reach, the Pentax HD DA 55-300mm f/4.5-6.3 ED PLM WR RE.
| Category | Best | Budget pick |
|---|---|---|
| Standard zoom Your everyday lens, from wide to short telephoto. | Sigma 17-50mm f/2.8 EX DC OS HSM (26-75mm eq · £349 new) | — |
| Telephoto zoom For sport, events, wildlife at a distance and compressed portraits. | Pentax HD D FA 70-210mm f/4 ED SDM WR (105-315mm eq · £1,099 new) | Pentax HD DA 55-300mm f/4.5-6.3 ED PLM WR RE (83-450mm eq · £210 used) |
| Wide-angle For landscapes, architecture, interiors and the night sky. | Pentax HD DA 11-18mm f/2.8 ED DC AW (17-27mm eq · £660 used) | — |
| Portrait prime Flattering perspective and blurred backgrounds. | Pentax HD D FA* 50mm f/1.4 SDM AW (75mm eq · £400 used) | Pentax HD FA 50mm f/1.8 (75mm eq · £199 new) |
| Fast standard prime Small, bright and cheap: the best first upgrade from a kit zoom. | Sigma 35mm f/1.4 DG HSM Art (53mm eq · £410 used) | — |
| All-in-one travel zoom One lens for everything when you don't want to swap. | Pentax HD DA 16-85mm f/3.5-5.6 ED DC WR (24-128mm eq · £290 used) | — |
| Super-telephoto For birds, wildlife and motorsport. | Pentax HD D FA 150-450mm f/4.5-5.6 ED DC AW (225-675mm eq · £1,110 used) | — |
Prices: MPB used where listed for Pentax K, otherwise typical new UK price (5 November 2026). Equivalent focal lengths account for the sensor size.
More for the K-3 Mark III
Frequently asked questions
What is the best lens for the Pentax K-3 Mark III?
For most people, a standard zoom such as the Sigma 17-50mm f/2.8 EX DC OS HSM, plus a fast prime like the Sigma 35mm f/1.4 DG HSM Art.
What lenses fit the Pentax K-3 Mark III?
The K-3 Mark III uses the Pentax K mount. Our database lists 13 lenses that fit natively. Because of the 1.5× crop factor, a 50mm lens frames like a 75mm lens on full frame.
Is the kit lens good enough for the K-3 Mark III?
Kit zooms are fine to start with. The biggest improvement usually comes from a brighter prime for low light and portraits, or a better standard zoom.
What telephoto lens should I get for the K-3 Mark III?
The Pentax HD D FA 70-210mm f/4 ED SDM WR is our top telephoto pick; the Pentax HD DA 55-300mm f/4.5-6.3 ED PLM WR RE is the budget choice.