Polar Alignment Error Calculator
Quantify your drift with scientific precision.
Focal Length (mm)
Pixel Size (µm)
Exposure Time (seconds)
Observed Drift (pixels)
Star Declination (degrees)
Please enter valid positive numbers.
0.00
Arc-minutes of Error
Excellent
How to measure your drift
Perform a long exposure on a star near the celestial equator (Declination ≈ 0°).
Measure the length of the star trail in pixels using your capture software (e.g., PixInsight or ASTAP).
Enter your equipment details above. The calculator will estimate your polar misalignment error in arc-minutes.
Note:
Values < 1 arc-min are considered excellent for most planetary or deep sky imaging.