Moon

Supermoons, Blue Moons and the Harvest Moon: What They Really Are and How to Photograph a Full Moon

By Still DarkPublished Sep 11, 2026Updated Sep 11, 202614 min read

Every few months a headline announces a supermoon, a Blue Moon or a "super Harvest Moon", and the Moon that rises looks a lot like last month's. None of these is an astronomical term. Two of them describe where a full Moon falls in the calendar, and one describes a difference in distance that you can hardly see. They're still a good reason to go out at moonrise, which is the best time to photograph the Moon anyway. The question we get most is when is the next supermoon, and the answer is November 24 or December 24, 2026, depending on whose definition you use. This guide explains each name, lists the full Moons through the end of 2027, and gives the exposure and timing you need for the photograph.

What a supermoon actually is

The Moon's orbit is an ellipse. Perigee, its closest point, is between about 221,500 and 230,200 miles from Earth's centre. Apogee is between about 251,000 and 252,700 miles. Perigee comes round every 27.55 days and full Moon every 29.53, so a few times a year a full Moon falls within a day or so of perigee. That's a supermoon.

The word doesn't come from astronomy. The astrologer Richard Nolle coined it in 1979 in Dell Horoscope: a new or full Moon "within 90% of its closest approach to Earth", meaning in the closest tenth of the apogee-to-perigee range. Fred Espenak's tables apply that rule year by year, which works out to a limit near 228,400 miles. Timeanddate uses a fixed limit of 223,694 miles. There's no official definition, which is why one list shows three supermoons in a year and another shows one.

The difference is real but small. A perigee full Moon is up to 14% wider than an apogee "micromoon" and about 30% brighter. Compared with an average full Moon it's about 7% wider and 15% brighter. The disc is 29.3′ across at apogee and 34.1′ at perigee, so about half a degree either way. With nothing beside it for scale nobody can see a 14% change, though you may notice the extra brightness. The enormous supermoon people talk about is the Moon illusion at moonrise, and that happens every month.

Why the rising Moon looks huge, and why it's orange

A rising Moon looks huge. If you photograph it and measure it, it's the same width on the sensor as the same Moon four hours later, high in the sky. It's actually slightly smaller. On the horizon you're farther from it by about Earth's radius (1.5% of the distance), and refraction lifts the lower limb more than the upper, which flattens the disc by a few percent. The rest happens in your head. The brain treats the horizon as farther away than the zenith and scales up whatever it sees there, as in the Ponzo illusion. Nobody has fully explained it yet.

The colour is real. On the horizon, moonlight passes through a lot more air than it does overhead, and air scatters blue light more than red. The light that reaches you is orange, or sometimes deep red through smoke. It's the same Rayleigh scattering that reddens the setting Sun. The colour fades to white as the Moon climbs.

What a Blue Moon is, and when the next one falls

There are two definitions, and neither is about colour.

• Monthly: the second full Moon in a calendar month, roughly every two and a half years. May 2026 had one (May 1 and May 31), and 2027 has none.
• Seasonal: the third full Moon in an astronomical season (equinox to solstice) that holds four rather than three. This is the older rule, from the Maine Farmers' Almanac. The monthly version comes from a 1946 Sky & Telescope article that misread the almanac, and the mistake stuck. The next is May 20, 2027. The season from the March 20 equinox to the June 21 solstice has full Moons on March 22, April 20, May 20 and June 19.

The Moon only looks blue through volcanic ash or fire smoke. That's rare, and it has nothing to do with the calendar.

The Harvest Moon and why it rises early

The Harvest Moon is the full Moon nearest the September equinox, usually in September, occasionally October. In 2026 the equinox is September 23 at 00:06 UTC and the Harvest Moon is September 26 at 16:49 UTC. In 2027 it's September 15 at 23:04 UTC. The full Moon after it is the Hunter's Moon.

What's different about it is when it rises. On average the Moon rises about 50 minutes later each night, because it moves about 13° eastward per day and Earth has to turn that much further to bring it up. But the delay depends on the angle the Moon's path makes with the horizon. Around the September equinox, from mid-northern latitudes in the evening, the ecliptic meets the eastern horizon at its shallowest angle of the year. The Moon's daily movement is then mostly along the horizon rather than below it, and each moonrise comes only 20–30 minutes after the previous night's. You get a bright Moon low in the east right after sunset on four or five evenings in a row. That makes it the easiest full Moon of the year to photograph. If you lose one evening to cloud, the next is nearly as good. In the southern hemisphere the same thing happens around the March equinox.

Full Moon names

The common names come from the Farmers' Almanac and go with the calendar month. The Harvest Moon is the exception, because it follows the equinox.

Full Moon and supermoon dates, October 2026 to December 2027

Times are the instant of full Moon in UTC, from Fred Espenak's phase tables. Convert to your zone before deciding which evening is "the night before". A time just after midnight UTC can fall on a different date where you are.

So the answer to "when is the next supermoon" depends on whose rule you use. The rest of 2026 has one or two, and 2027 has one or two. The three penumbral eclipses of 2027 only shade one edge of the disc faintly. The next total lunar eclipse is December 31, 2028.

How to photograph the full Moon: exposure and focal length

The full Moon is a grey rock in full sunlight, about as bright as a sunlit road at noon, whatever the sky around it looks like. A meter that averages the frame reads mostly black sky and overexposes the disc to white. So:

1. Start with Looney 11: f/11 and a shutter of 1/ISO. ISO 100 at 1/125 s, ISO 200 at 1/250 s, ISO 400 at 1/500 s. It's Sunny 16 opened one stop, because the Moon reflects less than a daytime scene. Any equivalent exposure works.
2. Correct for altitude. Looney 11 is for a full Moon high in a clear sky. A Moon just above the horizon is dimmed by the same air that turns it orange, and it needs 2–4 stops more. Put the disc in the upper quarter of the histogram, off the right edge. A supermoon needs no extra exposure, because surface brightness doesn't change with distance. Only the size does.
3. Spot meter or go manual. If you meter, put the spot on the Moon and add about +1 stop.
4. RAW, bracketed a stop either side. The full Moon has no shadows and looks flat, but you can bring the contrast back in processing.
5. 1/250 s or faster, because unsteady air makes the limb ripple.
6. Tripod, mirror lock-up or electronic shutter, remote or 2-second timer. Manual focus at maximum magnification on a crater rim, not the bright limb.

On the sensor the half-degree disc is roughly the focal length divided by 109 across, so 400 mm gives a 3.7 mm Moon. How big that looks depends on the sensor.

A 24-megapixel full-frame sensor at 400 mm puts the Moon across about 620 pixels, which is enough for a clean crop. For a Moon that looks big in a landscape you need 600 mm or more and a foreground several miles away. For craters and the terminator rather than the whole disc, see photographing the Moon with a telephoto lens.

Shoot the day before full, not the day of

On the full-Moon date the Moon rises at about sunset, opposite the Sun, and by the time it clears the horizon haze the landscape is dark. You get a bright disc over a black silhouette, and no single exposure holds both. The evening before, the Moon is 97–99% lit, which nobody can tell from full, and it rises 30–50 minutes before sunset while the landscape is still in daylight. For 15–20 minutes, Moon, sky and ground are within two or three stops of each other. The morning after works the same way in reverse. The Moon sets after sunrise over ground lit by low sun. (The timetable for every phase is in Moon phases for photographers.)

1. Read the times: moonrise, sunset and the moonrise azimuth for the evening before full, at your location.
2. Find a foreground on that azimuth, low on the horizon and far enough away to be sharp at your focal length. The Moon climbs roughly 10° in its first hour.
3. Arrive 30 minutes before moonrise. The Moon appears dim and orange, sometimes hard to find in the haze, and brightens 2–3 stops in the next quarter hour. Keep re-metering, because the exposure you set at moonrise is wrong ten minutes later.
4. Bracket three frames at 1-stop steps.
5. If the range is still too wide, take one frame for the ground and one for the Moon from the same tripod position, minutes apart, and blend them. Keep the Moon at the size and place the lens recorded. A Moon pasted in at three times its real size is a composite, not a photograph, and people can tell.

On a phone: turn night mode off, or it stacks long exposures for the sky and turns the Moon into a white blob. Tap and hold on the Moon to lock exposure there and drag the slider down until the disc shows texture. Use the longest real lens the phone has. Beyond the 3× or 5× telephoto, zoom is only a crop, and a half-degree Moon covers only a few dozen pixels on the main camera. A phone does better with the twilight scene and a small, correctly exposed Moon in it, and that can be a good picture.

Common mistakes

• Going out on the full-Moon date and finding the landscape black by the time the Moon is up. Go the evening before.
• Auto exposure, which averages the black sky and burns out the disc.
• Expecting a supermoon to look bigger. The eye can't judge a 7% change in an isolated disc.
• A slow shutter on a long lens. Keep it at 1/250 s or faster and raise ISO instead.
• Guessing the moonrise point. The azimuth shifts by degrees a night, so check it for the date.

FAQ

Sources and further reading

• Fred Espenak, AstroPixels — Phases of the Moon: 2001 to 2100 (all full-Moon dates and UT times in the table).
• Fred Espenak, AstroPixels — Full Moon at Perigee (Supermoons): 2001 to 2100 (the 90% rule, supermoon dates and distances for 2026–2027).
• NASA Science — Supermoons (definition; 14% bigger and 30% brighter than the year's faintest Moon; hard to detect by eye).
• NASA Science — The Moon Illusion: Why Does the Moon Look So Big Sometimes? (the horizon Moon is the same width; Ponzo illusion).
• EarthSky — When is the next Blue Moon? (monthly vs seasonal definitions, Maine Farmers' Almanac and the 1946 Sky & Telescope article, May 20, 2027).
• Farmers' Almanac — Full Moon Names (the month names and the Harvest Moon rule).