These are the best Sigma lenses for astrophotography when you want fast apertures, low sagittal coma, and repeatable manual focus for Milky Way landscapes, tracked mosaics, and tele-constellation fields—across full frame and APS-C—and here’s what to look for as you buy: prioritize speed (ƒ1.2–ƒ1.8 for short, clean subs; ƒ2–ƒ2.8 for lighter kits), disciplined off-axis performance (tight coma/astigmatism in the corners), mild field curvature, a long, predictable focus throw with a trustworthy infinity position (verify in daylight and tape it), strong flare resistance for moon and lanterns, manageable vignetting you can calibrate with flats, filter friendliness (front threads vs bulbous fronts needing a 100mm holder or rear gels), consistent color across a set, and weight you’ll actually hike with; for timelapse/video, favor lenses with declickable or finely stepping apertures, quiet AF you can disable, and restrained breathing. Full-frame wide-field heroes: 14mm ƒ/1.4 DG DN | Art (the Milky Way monster with disciplined corners), 20mm ƒ/1.4 DG DN | Art (balanced “stars + subject” focal with excellent contrast), and 24mm ƒ/1.4 DG DN | Art (environmental night scenes and blue-hour city/astro blends); add 35mm ƒ/1.2 DG DN | Art when you want dramatic wide-normal separation for starry foregrounds, and the 14–24mm ƒ/2.8 DG DN | Art for corner-clean ultra-wide zoom convenience on travel nights (pack a holder for filters) or the 16–28mm ƒ/2.8 DG DN | Contemporary for a lighter, threaded-front alternative. Specialty wides worth a look: 15mm ƒ/1.4 DG DN Diagonal Fisheye | Art for 180° star domes with a bright T-stop and surprisingly tidy points once stopped a touch. Tele-nightscape and constellation compression shine with the 105mm ƒ/1.4 DG HSM | Art (“bokeh master” that also excels on moonlit ridgelines) and the 135mm ƒ/1.8 DG HSM/DG DN | Art—razor detail on stars, pleasing micro-contrast, and beautiful airglow gradients for panels and mosaics. Macro-accurate foreground detail under stars belongs to the 105mm ƒ/2.8 DG DN Macro | Art, which doubles as a focus-stacking beast for night product or illuminated textures. APS-C travelers should anchor with the 16mm ƒ/1.4 DC DN | Contemporary (tiny, low-coma legend), add the 23mm ƒ/1.4 and 30mm ƒ/1.4 DC DN | C for “35/45-equiv.” night storytelling, and reach for the 56mm ƒ/1.4 DC DN | C for tele constellations; the 10–18mm ƒ/2.8 DC DN | Contemporary is the featherweight rectilinear ultra-wide for crop bodies, great for timelapse and tight locations. Practical buyer tips: pick focal length by scene—14–16mm for arches and big sky, ~20mm for balanced foreground + core, 24–35mm for tracked mosaics and city night, 85–135mm for constellation fields and compressed landscapes; favor threaded fronts (20/1.4, 24/1.4, 16–28/2.8, I-Series 17/4 & 20/2) if you rely on anti-dew filters or NDs, budget a 100mm holder for bulbous lenses (14/1.4, 14–24/2.8), and standardize filter sizes where possible; if you hike far, weigh the extra stop of the Art primes against the carry-everywhere 16–28/2.8 or DC DN primes—you’ll get more keepers from glass you bring. Shooting tips: start around ISO 3200–6400 and 10–20 s on full frame (use the 500-rule FF / 300-rule APS-C to cap trailing), focus via 10× live-view on a bright star and tape the ring, shoot wide open on the 14/1.4–20/1.4 and test a 1/3–2/3 stop down if corners need discipline, capture a low-ISO, longer exposure foreground to blend with your sky, disable IBIS on a locked tripod, use a soft heater or hand warmers to fight dew, and panel-stitch for ultra-wide resolution without stretching the edges. Whether you’re mapping the galactic core above sea stacks, stitching tracked mosaics across a desert vista, or compressing Scorpius over moonlit peaks, the best Sigma astro lenses combine fast, coma-tamed optics, repeatable focusing, and sensible ergonomics—so your night files are sharp, bright, and a joy to grade and print.