StarCast · Night Sky Planning
How Does Moon Phase Affect Night Photography?
Moon illumination is one of the biggest variables in Milky Way planning. LightCast StarCast tracks moon phase, illumination percentage, and rise and set times for your location every night.
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Phase by phase
What Each Moon Phase Means for Your Shoot
Moon illumination is measured as a percentage of the visible surface that's lit. Even a 30% moon is bright enough to noticeably wash out the Milky Way's faint outer structure. The usable new moon window for serious astrophotography is roughly 7 to 10 days centered on the new moon date — and within that window, moonrise and moonset times matter too.
New Moon (0–10%)
Ideal for Milky Way. Darkest skies of the month. Maximum contrast on faint galactic structure and deep sky objects.
Crescent (10–25%)
Usable. Minimal sky brightening. Moon sets relatively early, leaving a dark window after moonset. Good for most Milky Way work.
Quarter (25–50%)
Marginal. Noticeable sky brightening when moon is up. Plan around moonrise and moonset times to find the dark window.
Gibbous (50–90%)
Difficult for Milky Way. Significant sky glow. Usable for star trails and foreground-lit landscape work when moon is up.
Full Moon (90–100%)
Not for Milky Way. Sky too bright. Excellent for star trails, light painting, and moonlit landscape photography.
Any Phase
Check moonrise/set. Even a gibbous moon has a dark window before it rises or after it sets. StarCast shows both times each night.
More than just the phase
Why Moonrise and Moonset Time Matter as Much as Phase
A full moon that rises at 3am still leaves a dark window from astronomical twilight end until moonrise. A crescent moon that rises at 9pm can compromise the early evening even though the illumination percentage looks acceptable. StarCast shows moon illumination, moonrise, and moonset together so you can identify the exact dark window within any phase, not just whether the moon phase is technically favorable.
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StarCast Push Alerts
StarCast scores every night using cloud cover, moon illumination, moonrise and moonset, Bortle class, and atmospheric transparency. Push alerts notify you when a high-scoring night is forecast so you don't miss the new moon window when conditions also line up.
Common Questions
What moon phase is best for Milky Way photography?
New moon, or within 3 to 4 days of it.
10% illumination or less has minimal impact on sky brightness. Above 25%, the Milky Way's faint outer structure begins losing contrast. StarCast shows moon illumination percentage each night — available in the
LightCast iOS app and at
lightcastsuite.com/starcast.
Can you photograph the Milky Way with a full moon?
Not effectively for wide-field Milky Way. Full moon sky brightness is similar to deep twilight and washes out the galactic core contrast entirely. Full moon nights are better used for star trails, light painting, and moonlit landscape work.
Does moon phase affect star trail photography?
Less than Milky Way photography. A bright moon illuminates the foreground naturally during long star trail exposures, which many photographers prefer. Full moon nights are a legitimate choice for star trail sessions.
How do I find the dark window when the moon is up part of the night?
Check moonrise and moonset times alongside the phase. The dark window is the overlap between astronomical darkness and moon below the horizon. StarCast shows all three times — astronomical twilight end, moonrise, and moonset — so you can identify the window precisely.
What is LightCast StarCast?
StarCast scores night sky conditions from 0 to 100 using cloud cover, moon illumination, moonrise and moonset, Bortle class, and atmospheric transparency for any location. Push alerts notify you when conditions are worth the drive. Free at
lightcastsuite.com/starcast, with push notifications in the
LightCast iOS app. $2.99/month after a 7-day free trial.