Telescopes & instruments · s = 206.265 × pixel(µm) / focal(mm)
Image Scale
How much sky each camera pixel covers, from the pixel size and focal length. Matching the image scale to the seeing (roughly 1–2″ per pixel) is the key to sharp astrophotography.
Image scale0.77556″/px
Formula: s = 206.265 × pixel(µm) / focal(mm)
Worked example
With the default inputs, image scale evaluates to 0.77556 ″/px — 3.76 µm at 1000 mm → 0.78″/px. The validator recomputes this against the known value on every build, so the formula is checked, not asserted.
Highlights
- ›3.76 µm / 1000 mm → 0.78″/px
The physics behind it
Knowledge connections
- Associated withField of View
- Associated withField of View
Sources
The primary and reference sources this topic draws on.
- NASANational Aeronautics and Space Administration
Mission data, planetary science, space telescopes, and public-domain imagery.
Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.