These are the best Pentax lenses for low light when you want fast apertures, clean contrast, and confident handling in compact, weather-ready K-mount kits for night streets, interiors, concerts, and candlelit portraits. The modern full-frame flagships—the HD PENTAX-D FA★ 50mm f/1.4 SDM AW and HD PENTAX-D FA★ 85mm f/1.4 SDM AW—deliver wide-open sharpness, gentle highlight roll-off, and AW sealing that keeps you shooting through drizzle; pair them with the HD PENTAX-D FA 21mm f/2.4 Limited DC WR for a compact, story-rich wide that excels at blue hour and environmental scenes. Classic FA Limited primes bring speed with character: 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) all stay small and render beautifully in available light. On APS-C, the smc/HD PENTAX-DA★ 55mm f/1.4 SDM is the low-light portrait pick—creamy, skin-friendly bokeh with weather-resistant confidence—while the super-handy HD PENTAX-DA 35mm f/2.8 Macro Limited doubles as a crisp night walk-around with close-focus detail; budget shooters can lean on the DA 50mm f/1.8 or DA 35mm f/2.4 for fast, lightweight evening kits. Fast zoom coverage matters for events: run the HD PENTAX-D FA 24–70mm f/2.8 ED SDM WR and HD PENTAX-D FA* 70–200mm f/2.8 ED DC AW on full frame for ceremony-to-reception versatility, or the HD PENTAX-DA★ 16–50mm f/2.8 ED PLM AW and HD PENTAX-DA★ 11–18mm f/2.8 ED DC AW on APS-C for quick AF, sealed builds, and constant f/2.8 in dim venues. Astro-leaning nights benefit from low-coma wides: the IRIX 15mm f/2.4 (K) and Laowa 12mm f/2.8 Zero-D (K) keep stars tight toward the corners, while the Samyang 35mm f/1.4 and 85mm f/1.4 (K-mount) offer great value and smooth manual throws for deliberate focus pulls after dark; the Samyang 135mm f/2 is a cult classic for tele-nightscapes and dreamy stage portraits. Across the board, Pentax body strengths amplify low-light results: in-body Shake Reduction steadies slower shutters for cleaner ISO, Astrotracer turns wide primes into pinpoint star tools without a tracker, Pixel Shift yields ultra-clean detail on static scenes, and Quick-Shift MF lets you refine focus instantly after AF locks; WR/AW sealing across many lenses keeps you working in rain and sea spray. Practical picks: choose D FA★ 50/1.4 and 85/1.4 for flagship full-frame night work, add D FA 21/2.4 Limited for compact wide scenes, run DA★ 55/1.4 on APS-C for portraits, keep DA 50/1.8 or DA 35/2.4 for affordable speed, and lean on D FA 24–70/2.8 or DA★ 16–50/2.8 PLM when zoom flexibility in dim light decides the shot. Shooting tips: use TAv to lock shutter and aperture while letting ISO float, enable SR for handheld stills (but disable on tripods), focus with live-view magnification/peaking for precision at f/1.4, and give subjects distance from backgrounds for larger, cleaner bokeh balls. Whether you’re mapping neon on wet pavement, working a candlelit reception, or pulling clean stars over city glow, the best Pentax lenses for low light combine fast glass, robust sealing, and in-body stabilization—so your night files stay sharp, smooth, and richly colored.