How is sun azimuth measured?

Azimuth is measured clockwise from true north: 0° = north, 90° = east, 180° = south, 270° = west. This matches surveying convention and is what most camera/sun-tracker apps expect.

How do I know if I'm in the path of totality?

This calculator uses astronomy-engine SearchLocalSolarEclipse for your coordinates and eclipse date. If the result is 'total', your site sees the Moon fully cover the Sun at peak. Partial means only a partial phase; annular means a ring remains. Cross-check with NASA or the Board Gaming Hub Eclipse Predictor 3D map before travel.

What altitude do I need for eclipse photography?

For horizon compositions, sun altitude tells you how high to tilt the camera. During totality the corona is visible only when the photosphere is covered — filters come off only in the total phase. Low altitudes (near sunset) favor foreground silhouettes but increase atmospheric distortion.

All tools Print with PE stamp box Designed for sealed engineering submittals — print drops PE stamp + signature block at the end.

Eclipse Sun Position

Solar eclipse field calculator for photographers and surveyors: sun altitude and azimuth at any latitude, longitude, and UTC date/time, plus a local eclipse check (total, annular, partial, or none). Defaults to Hornedo, Cantabria — Aug 12 2026 18:27 UTC on the 2026 total eclipse center line.

Open calculator (free, verifiable): Sun position uses astronomy-engine (Moshier ephemeris, MIT-licensed) with an inline Meeus fallback if the CDN is blocked. Totality checks use the same SearchLocalSolarEclipse pipeline as NASA/Espenak catalogs.

3D path map (Board Gaming Hub): Scrub the full umbral path on a rotatable globe — Eclipse Predictor · 2026 & 2027 eclipse guide.

Educational astronomy tool — verify contact times against NASA eclipse.gsfc.nasa.gov before expedition logistics.

Latitude, φdegrees (+N, −S)

Longitude, λdegrees (+E, −W)

Date (UTC)calendar date at observer

Time (UTC)24-hour, Zulu

Observer elevationm above sea level (refraction correction)

Sun altitude, h—degrees above horizon

Sun azimuth, A—degrees from true north (clockwise)

Sun declination, δ—degrees

Hour angle, H—degrees (0 at meridian transit)

Eclipse at this site—on selected UTC date

Peak eclipse (UTC)—greatest eclipse for this location

Totality duration—total phase only

Ephemeris source—

Defaults: Hornedo (43.3872°N, 3.7478°W), Aug 12 2026 18:27 UTC — on the Aug 12 2026 total eclipse path in northern Spain. Azimuth is surveying convention (0° = north, clockwise). Altitude includes standard atmospheric refraction near the horizon.

Local hour angle (degrees):

$$ H = \mathrm{GST} + \lambda - \alpha $$

Sun altitude and azimuth (spherical astronomy):

$$ \sin h = \sin\phi\sin\delta + \cos\phi\cos\delta\cos H $$

$$ \tan A = \frac{\sin H}{\cos H \sin\phi - \tan\delta \cos\phi} $$

Totality check: SearchLocalSolarEclipse (astronomy-engine) finds partial, annular, or total eclipse visible at (φ, λ) within ±2.5 days of the selected date.

h altitude above horizon · A azimuth from true north · φ latitude · λ longitude · δ Sun declination · α Sun right ascension · H hour angle · GST Greenwich sidereal time.

Using sun position for eclipse photography

Altitude tells you how high to point the lens; azimuth tells you which compass bearing to face. For a horizon composition (lighthouse, mountain ridge, cathedral spire), pick a site where the eclipsed Sun sits where you want it in the frame at peak — this calculator gives you the numbers at any UTC instant, not just at greatest eclipse.

During the partial phases, use certified ISO 12312-2 solar filters on every optical surface. Remove filters only during the brief total phase when the photosphere is fully covered and the corona is visible.

Path of totality vs. partial zone

The umbra (path of totality) is typically 100–250 km wide for a total eclipse. Outside that corridor you see only a partial eclipse — still dramatic, but no corona and no safe filter removal. The 2026 eclipse sweeps from the Arctic through Greenland, Iceland, and northern Spain; the 2027 eclipse offers over six minutes of totality across Spain and North Africa.

For interactive path exploration, use the free Eclipse Predictor 3D globe or read the 2026 & 2027 solar eclipse guide.

Accuracy and limits

Positions are sub-arcminute with astronomy-engine (Moshier ephemeris). The inline fallback uses a truncated Meeus solar theory — adequate for framing, not for sub-arcsecond surveying. Eclipse contact times should be cross-checked with NASA GSFC or IOTA publications before booking travel.

Reference: Meeus, J. (1998). Astronomical Algorithms, 2nd ed., Willmann-Bell, ch. 25–27. Cross, D. (astronomy-engine). github.com/cosinekitty/astronomy. Espenak, F., Meeus, J. NASA Five Millennium Canon of Solar Eclipses.

Related resources

Eclipse Predictor — 3D path map (Board Gaming Hub)
2026 & 2027 Solar Eclipse Guide
Linear interpolator (table lookups)

Eclipse Sun Position

Using sun position for eclipse photography

Path of totality vs. partial zone

Accuracy and limits

Related resources

Monthly engineering case studies