Astrophotography Pixel Scale Calculator
Estimate angular sampling from camera pixel pitch and the effective focal length of your imaging system.
Calculate locally
No account, API or uploaded inputs. All calculations run in this browser.
Worked example
A 5 micrometre pixel at 1000 mm focal length samples approximately 1.031324 arcseconds per pixel. Doubling focal length halves the scale. For 2×2 binning, use twice the native pixel pitch.
Method and units
The small-angle sampling scale is (180/π) × 3600 × pixel pitch/focal length. Convert micrometres to millimetres by dividing by 1000 first; equivalently scale ≈ 206.264806 × pitch in micrometres / focal length in millimetres.
What this result means
Sampling is not resolving power. Seeing, tracking, diffraction, focus and processing set the recorded detail. Enter effective focal length after any reducer or Barlow. This is a local paraxial scale; distortion and a very wide field cause scale variation. Binning does not create new optical detail.