← All calculators

Resolution and Sampling

Know what the aperture can resolve.

Compare the telescope's diffraction limit with your camera sampling and local seeing. Change any input to see the consequences immediately.

Inputs

Optical path

Use physical dimensions and canonical units for the estimate.

Unit: mm
Unit: nm
Unit: mm
Unit: µm
Unit: ×
Unit: arcsec

Calculated now

Resolution and sampling

These are ideal optical estimates, not a guarantee of image detail.

Rayleigh limit
0.692at 550 nm
Dawes estimate
0.580empirical double-star limit
Image scale
0.776″ / px3.76 µm effective pitch
Pixels per Rayleigh limit
0.89undersampled
Pixels per seeing FWHM
2.58for 2.0″ seeing
Critical focal ratio
f/11.22,241 mm for 2 px

How to read this

The Rayleigh limit is the ideal diffraction separation. The detector samples that scale with the image scale; two pixels per Rayleigh limit is the minimum target used here, while seeing usually becomes the practical limit from the ground.

θᵣ = 1.22 λ / D · 206264.806″ image scale = 206.265 p / f

Atmospheric turbulence, focus, obstruction, tracking, contrast, processing, and target brightness can all reduce real-world resolution. Treat these outputs as planning guidance.