Rig Health
Your imaging train's checkup, measured from the telemetry you already stream: how focus moves with temperature, whether your parfocal offsets match reality, how fast focus decays after an autofocus, and the slow drifts that mean tilt or a sensor problem.
Focus vs temperature
Focus moves 8.3 steps per °C — set N.I.N.A.'s autofocus temperature trigger to ~3°C so drift stays under ~25 steps.
Parfocal offsets
| Filter | Measured | Configured | n |
|---|---|---|---|
| L | 0 | 0 | 21 |
| Ha ⚠ | +38 | -10 | 7 |
| OIII | -12 | -15 | 5 |
⚠ measured ≠ configured by >25 steps — update the rig's parfocal offsets.
Star eccentricity
Rising eccentricity across nights usually means growing tilt, sag, or mount/guiding wear — not sky conditions.
Sky background
A steady climb (same targets, same moon) points at dark-current growth, a light leak, or encroaching light pollution.
Field flatness
Tilt trend
One soft corner → adjust the tilt plate toward it (a quarter-turn at a time). Soft edges all around → fix backfocus spacing, not tilt. A tilt number that climbs across nights means something is moving — check every connection for sag.