Pentax's premium DX telephoto prime — the DA 300mm f/4 with SDM motor and weather sealing.
The Pentax SMC DA 300mm f/4 ED IF SDM is a premium APS-C telephoto prime providing 450mm equivalent reach on Pentax K-mount cameras. The SDM ultrasonic motor provides lens-based AF. ED and IF elements ensure optical quality. Not weather-sealed but the SDM motor and ED optics make it Pentax's premium long telephoto for the DX system.
Outstanding sharpness from the dedicated 300mm design. The 450mm equivalent provides serious wildlife and sports reach. SDM motor provides quiet, precise AF. ED elements control chromatic aberration. IF design prevents barrel extension. Benefits from Pentax in-body SR stabilisation — critical at this focal length for handheld shooting.
Pentax K mount, APS-C (DA). Filter thread is 77mm. Weight approximately 1,070 grams — moderate for a 300mm. Build quality good but not weather-sealed like the DA* series. SDM motor is lens-based — independent of body motor. The 300mm f/4 is Pentax's dedicated long prime for the DX system.
Available at moderate prices. Check SDM motor and AF accuracy. A serious telephoto prime for Pentax DX. The 450mm equivalent with body SR provides good handheld telephoto capability. The SDM AF is a genuine advantage. One of the best long prime options in the Pentax K-mount DX system.