Celeris – Photo Planner

Stefan Engel

In-app purchases

About this app

See the shot before you take it.

Celeris is next-generation photo planning for every landscape picture: it plans the shot for any place and any moment against the real terrain — the sun dropping behind a ridge at golden hour, the blue hour over a town, a fog sea below the lookout, a rainbow opposite the sun, the moon beside a castle, the Milky Way over it at night, an eclipse, the station's crossing. Day, night and everything in between. The map, time scrubber and sky stay together on one screen.

REAL TERRAIN IN 3D
In the 3D view Celeris draws the real terrain from Copernicus WorldDEM-30, fetched once and then on the device: sun and moon light the land from where they really stand, the slopes cast shadows, the ridge is your horizon; beside the almanac time stands the moment at the ridge. Terrain is available across Europe and the United States.

LIGHT THROUGH THE DAY
The endless time scrubber is a band of twilight colour: golden hour, blue hour, the twilight phases, with the sun's arc and the moon's on it. The sun is drawn at its true angular size and gets the sunstar of your aperture at a terrain or model edge; a possible rainbow stands opposite the sun.

GROUND FOG
Where terrain is fetched, Celeris lays a fog layer in the valley: set its top and the visibility, and see whether the castle stands out of the fog sea. The fog is a simulation to picture the shot with, not a forecast.

THE CAMERA VIEW
Set focal length, orientation and direction: see what a full-frame camera captures; on the map that frame becomes a cone, in panorama mode a grid of overlapping frames. 10 to 1200 mm.

FOREGROUND
Build in the 3D editor what stands in front of you from cuboids, wedges, hip roofs and footprints, in metres at the real ground height; stand on it. And over 100 surveyed models of castles, structures and rock formations.

THE MOON
Phase and position, topocentric where you stand, moonrise beside your subject, earthshine on the dark part. In the sky it is a body, not an icon.

THE NIGHT
The Milky Way band and the galactic centre, the zodiacal light, stars that twinkle, with a white core and a coloured skirt. Light pollution is modelled from satellite night lights with a Bortle class — in the full version drawn in the 3D sky, washed over the map in the atlas colours, listed as the dark places nearby. With them dark nights, the month calendar, the catalogue: 8,920 stars, 110 Messier objects, Mercury to Neptune with Saturn's rings.

ECLIPSES AND THE ISS
Every solar and lunar eclipse your place gets, years ahead, at the real horizon. And every crossing of the sun and the moon by the station, every close pass within 2° — to the second. Orbital elements come from CelesTrak.

PLANS AND ON LOCATION
A plan holds the moment, the place, the object, the bearing and the lens with a rendered picture of the frame, and is passed on as a card. On site, AR lays the sky over the camera picture and leads you to the standpoint.

WIDGETS
Home-screen widgets show main events, the Milky Way, ISS crossings and the next plan; a notification counts down to it.

LOCATION AWARE, HONEST MATHS
GPS, place search, saved places, viewpoints and summits on the map, the planned place's time zone — and the standard methods of spherical astronomy.

FREE AND FULL VERSION
Celeris is free and stays free. Only how far ahead it plans is limited: 48 hours from now. The full version opens every date and unlocks the month calendar, the eclipse list, the widgets and the light pollution features. One payment, no subscription.

Calculations happen on device. No ads, no trackers, no account. Plans, places and your own 3D objects can optionally sync through your own Google Drive. German and English.

The star catalogue is derived from the HYG database by Astronexus and OpenNGC by Mattia Verga, both under CC BY-SA 4.0. Sources and further licences are listed in the app under More → Licences.

What’s new

Celeris 2.1: light pollution with a Bortle class, in the full version drawn into the 3D sky, laid over the map and searchable as dark places. The zodiacal light, twinkling stars, stars with a white core and a coloured skirt, diffraction spikes at long focal lengths, a play button at real time. Panorama mode. The planets Mercury to Neptune, Saturn with its rings, the lens up to 1200 mm. An ISS widget and a countdown to your next plan. Wish for and report 3D models, straight from the app.