Polar Alignment

The "before you do anything else, get the mount's RA axis pointed at the celestial pole" tier. A 3-arcminute polar misalignment is enough to noticeably trail stars at the edges of a 1-hour exposure — and no amount of autoguiding can fix the field rotation it produces.

For the autoguider that runs after polar align is done see Autoguiding; for the session manager that orchestrates polar align step inside the larger flow see Mount & Session Control; for plate solving (which underlies many polar-align routines) see Plate Solving.

Software polar align (free or low-cost)

• ★ ★ N.I.N.A 3-Point Polar Alignment — free, plug-in built into N.I.N.A. Three plate-solved exposures at different RA positions; software computes the polar-axis offset and walks you through altitude / azimuth knobs until the error is under target. Doesn't require a view of Polaris — works from the southern hemisphere or a tree-blocked north horizon. The cleanest free Windows method in 2026.
• ★ SharpCap PolarAlign — paid feature in SharpCap Pro (~$15/yr). Same plate-solve-based method, predates the N.I.N.A version. Wildly popular; works without seeing Polaris; Windows only.
• ★ KStars / Ekos Polar Alignment — free, built into Ekos; same plate-solve principle; cross-platform (runs on a Pi at the mount). Two flavors: Polar Alignment Assistant (modern, plate-solve) and legacy alignment (drift). Default Linux/Mac/Pi answer.
• ASIAIR Polar Align — closed; built into the ZWO companion app; works only with ZWO cameras. Plate-solve-based.
• DARV (Drift Alignment by Robert Vice) — free script-based traditional drift align; works with anything but slow. Use as a check, not a primary method.

Hardware polar scopes / cameras

• ★ PoleMaster (QHY) — paid (~$300) USB camera that bolts onto the mount's polar-scope mount and uses field-of-Polaris pattern matching; very fast (1–2 minutes); QHY-only software but works without N.I.N.A / SharpCap. Ageing but still excellent; QHY also sells a smaller MiniPoleMaster for portable rigs.
• iOptron iPolar / iPolar Plus — built into iOptron mounts; equivalent function. Free with the mount.
• SkyWatcher Star Adventurer GTi / EQ6-R Pro built-in polar scope app — SkyWatcher's own; free with the mount.
• Polar scope (the actual reticle) — the reticle in the mount's polar axis; analog; pair with PolarFinder / PSAlign Pro mobile apps that show you where on the reticle Polaris should be at the current time.

Drift alignment (manual, traditional)

• PHD2 Drift Align tool — free; integrates with PHD2; the no-camera-on-Polaris fallback. Slow but reliable. See Autoguiding.
• DARV — short scripted drift; works in ten-minute increments.

Mobile polar-finder apps

• Polar Scope Align Pro (paid iOS, free Android) — shows Polaris position on the reticle for your time/location.
• PolarFinder — free Android.
• Stellarium mobile — has a polar-scope plugin you can configure.
• Sky Adventurer — paid; SkyWatcher-flavored; UI nicer than PolarFinder.

Southern hemisphere

There's no naked-eye pole star south of the equator. Plate-solve methods (N.I.N.A 3PPA, SharpCap PolarAlign, Ekos) work fine there. Avoid drift align unless you have all night.

What's changing in 2024–2026

• Plate-solve polar align is the default — works without seeing the pole, works in either hemisphere, fast. Buying a hardware PoleMaster makes less sense than it did pre-N.I.N.A.
• Smart scopes auto-align — Seestar / Vespera / Dwarf are alt-az; they don't need polar alignment, they manage field rotation in software. A real differentiator for casual users.
• Mount-native cameras — newer iOptron / SkyWatcher mounts include the camera; firmware does the math.

License / pricing summary

• Free: N.I.N.A 3-Point, KStars Ekos polar align, PHD2 drift align, mobile polar-scope apps (mostly).
• Paid (~$15/yr): SharpCap Pro.
• Paid (~$300): QHY PoleMaster (one-time hardware).

Pick this if…

• Free Windows, no Polaris view: N.I.N.A 3-Point Polar Alignment.
• Free Linux/Mac/Pi: KStars Ekos polar alignment.
• Cheapest paid Windows: SharpCap Pro ($15/yr); also gets you sensor analysis / live stacking.
• Hardware path, QHY ecosystem, fast field setup: PoleMaster.
• Smart scope: the scope handles it; relax.
• Star tracker (Star Adventurer / Move Shoot Move): mobile polar-finder app + the mount's reticle.