Two free geometry calculators for astrophotographers — work out the exact numbers your mount, dome, or roll-off roof needs, and verify them in 3D before anything gets bolted down.
A dome and a roll-off roof are fundamentally different geometry problems — they need separate tools, not one generic calculator bolted into a different shape.
Converts physical measurements into the exact signed fields NINA's dome-sync tab expects. Live 3D preview shows whether the shutter actually clears the OTA at every pointing. Full-sky coverage sweep, pier-side comparison, local horizon modeling, one-click NINA settings export.
Real wall, roof, and floor/ceiling obstructions — including the parked roof itself. Up to 4 telescopes on one mount, with swing-radius clearance checked against walls and against each other. Custom building shapes, flat/peaked/wedge roof profiles, exportable horizon file for NINA or Stellarium.
Both tools include an interactive 3D model of your observatory — drag to orbit, scroll to zoom. The shutter or walls turn red the moment a clearance problem appears, at whatever pointing you're testing.
The dome calculator's azimuth math is ported from NINA's own DomeSynchronization.cs — what you see here is what NINA actually computes, not a simplified stand-in.
Both tools are fully client-side HTML. Nothing you enter leaves your device. Save and load your setup as a local JSON file whenever you need to pick up where you left off.
Both calculators are released under the Mozilla Public License 2.0 — the same license NINA uses. The source is the HTML file itself; view source in your browser to read it. Contributions and forks welcome under those terms.