These are the best Pentax wide-angle lenses when you want edge-to-edge sharpness, clean flare resistance, and weather-ready handling for landscapes, architecture, city nights, and astro—across APS-C and full-frame K-mount bodies. Full-frame shooters should anchor with the HD PENTAX-D FA 15–30mm f/2.8 ED SDM WR, a tank-tough ultra-wide zoom with bright f/2.8, strong coma control, and gorgeous micro-contrast for blue-hour vistas and interior drama; pair it with the HD PENTAX-D FA 21mm f/2.4 Limited DC WR for a jewel-like prime that blends Limited-series rendering with modern coatings, weather sealing, and a natural, story-forward FOV that excels at environmental scenes and night streets. If you favor primes with character and reach into the classics, the smc/HD PENTAX-FA 31mm f/1.8 Limited delivers wide-normal glow and sunstars that print beautifully, while third-party ultra-wides expand your extremes: the IRIX 15mm f/2.4 (K) offers low-distortion speed with long, precise focus throw for astro and architecture, the IRIX 11mm f/4 (K) pushes to sweeping horizons with a huge image circle and excellent corner hold, and the Laowa 12mm f/2.8 Zero-D (K) brings rectilinear discipline for tight interiors and starry skies. On APS-C, the HD PENTAX-DA★ 11–18mm f/2.8 ED DC AW is the pro cornerstone—fast constant aperture, all-weather build, crisp corners, and snappy AF for mountain storms, city canyons, and Milky Way frames—while the smc/HD PENTAX-DA 12–24mm f/4 delivers classic, rectilinear coverage with punchy color for travel and architecture. Limited-series primes keep kits tiny without sacrificing bite: the HD PENTAX-DA 15mm f/4 Limited is a cult favorite for sunstars, flare control, and pocketability, and the HD PENTAX-DA 21mm f/3.2 AL Limited offers a slim, metal build with close-focus intimacy for cafés and alleys; add the HD PENTAX-DA 20–40mm f/2.8–4 Limited DC WR for a sealed, lightweight walk-around that starts wide with Limited rendering. Creative shooters can sprinkle in the HD PENTAX-DA 10–17mm f/3.5–4.5 Fisheye ED for bold curves and close-focus wide-angle (hood off, it even does near-circular tricks on K-1), while value hunters can reach for the Samyang 14mm f/2.8 (K) as a budget-friendly full-frame ultra-wide with manual precision. Across the lineup, Pentax body strengths elevate results: in-body Shake Reduction steadies twilight handhelds, Pixel Shift yields micro-detail on static scenes, Astrotracer unlocks pinpoint stars without a tracker, and WR/AW builds mean you keep shooting in wind, drizzle, and sea spray. Practical picks: choose D FA 15–30/2.8 for FF ultra-wide versatility, D FA 21/2.4 Limited when you want compact speed and signature rendering, and IRIX 15/2.4 (or Laowa 12/2.8) for prime-driven extremes; on APS-C, run DA★ 11–18/2.8 as the fast, sealed workhorse, add DA 12–24/4 for rectilinear travel, DA 15 Limited or DA 21 Limited when you want tiny metal optics with great flare control, and DA 20–40 Limited WR for a weather-sealed wide-to-normal companion. Field tips: use hyperfocal with focus peaking for fast street and ridge shots, stop down to f/5.6–f/8 for corner discipline (or f/2–f/2.8 on the fast glass for star work), shade bulbous fronts to tame sunballs, and lean on close-focus to anchor foreground textures that lead the eye. Whether you’re threading cathedral vaults, stitching wind-blasted panoramas, or mapping the galactic core over sea stacks, the best Pentax wide-angle lenses combine controlled optics, robust builds, and Pentax’s in-body tools—so you travel lighter, shoot longer, and bring home wide frames that grade and print beautifully.