Lumen: Golden Hour and Sky

umen is a planner for the light and the night sky, for photographers and anyone who waits outside for the right minute. For any place and day it works out the golden and blue hours, the three twilights, sunrise and moonrise with the direction of each, and when the core of the Milky Way stands in a dark sky. And it answers the question that decides a shot: when does the moon rise behind that tower, seen from where I will stand.

Everything is computed on your phone from its own ephemeris. No account, and your places never leave the device.

TODAY
• The day's light as one bar on the place's own clock: night, twilights, blue hour, golden hour, daylight
• Every event with its time and its azimuth: astronomical, nautical and civil dawn and dusk, sunrise, sunset, solar noon
• The golden and blue hours with the limits that produced them, in degrees of the sun's height
• The Moon: rise and set with directions, phase and how much is lit, distance in kilometres and apparent size in arc-minutes, the next full and new moon

YOUR LIMITS, NOT OURS
The golden hour has no official definition. Choose standard, narrow or wide limits, or set your own, and every time in the app follows. The limits are printed beside every result.

PATH
• The sun and moon across the horizon by direction, with a slider through the hours
• Lay the solstices and the equinox beside today to see where the light will move

PLAN: BEHIND YOUR SUBJECT
• A viewpoint, a subject and the height of its top, typed or measured by tilting the phone
• Every date and time in the coming year when the sun or the moon stands behind the top, grouped into runs of days, with the moon's phase
• The curve of the Earth and the bending of the air are taken into account for distant subjects
• A direction the sun can never reach from your latitude is answered with never, not with the nearest day

NIGHT
• The highest the Milky Way core can ever stand from your place
• Three conditions on one time axis: the core high enough, the sun below -18°, the moon down or thin, and the window where all three hold. No score: you see which one makes a night short
• The window length for each of the next 30 nights

ALSO
• A home-screen widget with the next golden hour and how much of the moon is lit
• Optional notes half an hour before the golden hour, and three days before a pass behind a saved subject
• Articles: why the golden hour has no definition, the night that never comes, where the core stands from where you live, back bearings, and what a supermoon really is
• Places from a built-in list of cities, typed coordinates, or the phone's rough position, with times always on the clock of the place

It works where the sky is hard: it says in words when astronomical night does not begin, when the sun does not set, and when the core never rises at your latitude, instead of drawing an empty window.

Free to install, with ads. A single one-time purchase removes them and unlocks every date in the year for your subjects, any number of saved plans, and the plan notes.