These are the best Pentax lenses for night photography when you want fast apertures, low coma, and confident manual focus for city neon, blue-hour streets, concerts, and Milky Way landscapes—across APS-C and full-frame K-mount bodies—and here’s what to look for as you buy: prioritize speed (f/1.4–f/2.8 for shorter, cleaner exposures), off-axis performance (tight coma/astigmatism in the corners for stars), flare resistance and controlled ghosts around bright lights, a long and repeatable MF throw with a clear distance scale (critical for infinity pulls), minimal focus shift as you stop down, stable front for filters (for city long exposures; bulbous-front ultra-wides need holders), WR/AW sealing for drizzle and sea spray, and manageable weight if you hike at night; on the body side, plan to leverage in-body SR for handheld city work (disable on tripod), Astrotracer for pinpoint stars, Pixel Shift for ultra-clean foreground blends, and TAv mode to lock shutter/aperture while ISO floats. Full-frame staples start with the HD PENTAX-D FA 15–30mm f/2.8 ED SDM WR (bright ultra-wide, strong corner hold, tough sealing) and the compact HD PENTAX-D FA 21mm f/2.4 Limited DC WR (jewel-like build, modern coatings, story-rich wide scenes); classic FA Limiteds add character for night people and places—the smc/HD PENTAX-FA 31mm f/1.8 Limited (wide-normal glow), FA 43mm f/1.9 Limited (buttery transitions), and FA 77mm f/1.8 Limited (portrait magic). Prime-driven astro and city extremes shine with third-party glass: IRIX 15mm f/2.4 (long, precise throw; low coma), Laowa 12mm f/2.8 Zero-D (rectilinear discipline in tight spaces), and Samyang/Rokinon 14mm f/2.8 (value ultra-wide with profile-fixable distortion); for faster nightscapes or tracked panos, Samyang 24mm f/1.4 and 35mm f/1.4 (K-mount) deliver speed with smooth manual throws, while the Samyang 135mm f/2 is a cult tele for compressed constellations and dreamy stage portraits. On APS-C, the HD PENTAX-DA★ 11–18mm f/2.8 ED DC AW is the pro ultra-wide cornerstone (fast, sealed, corner-clean), the smc/HD PENTAX-DA 12–24mm f/4 remains a rectilinear city-night workhorse, and the HD PENTAX-DA★ 16–50mm f/2.8 ED PLM AW brings modern optics and lightning-quick AF to dim venues; lightweight fast primes round out handheld nights—the DA★ 55mm f/1.4 SDM for portraits and gigs, DA 50mm f/1.8 and DA 35mm f/2.4 for affordable speed, and tiny Limiteds (DA 15mm f/4, DA 21mm f/3.2) that punch above their apertures when paired with Astrotracer. Practical buyer tips: if your priority is Milky Way corners, favor lenses known for low sagittal smear (IRIX 15/2.4, Laowa 12/2.8, D FA 15–30/2.8) and test at f/2–f/2.8; for ambient street and concerts, pick fast normals/short teles (D FA★ 50/1.4, D FA★ 85/1.4, DA★ 55/1.4) to keep ISO down and backgrounds smooth; if you shoot long-exposure cityscapes, prefer threaded fronts (67/77/82mm) for NDs and a solid hood for ghost control; hikers should balance speed vs carry—28–105 WR or DA 20–40 Limited WR often beats heavier glass you’ll leave in the car; and for tripod astro, choose lenses with repeatable MF and a hard-to-miss infinity mark. Shooting tips: use live-view magnification/peaking on a bright star to set focus, start around ISO 1600–6400 and 10–20s (use the “500-rule” on full frame or “300-rule” on APS-C to limit trailing), shoot wide open or stop 1/3–2/3 stop if corners need cleanup, disable SR on locked tripods, enable Astrotracer for longer subs, and capture a low-ISO, longer foreground frame to blend with your sky. Whether you’re mapping neon on wet pavement, freezing candlelit performances, or stacking the galactic core above sea stacks, the best Pentax lenses for night photography combine bright, coma-tamed optics, reliable focusing feel, and weather-ready builds—so your night files stay sharp, clean, and richly colored.