How to photograph a lunar eclipse

A lunar eclipse happens when the full Moon passes through Earth’s shadow. Unlike a solar eclipse, there’s no safety concern at all here — it’s just a dimmer, redder Moon, and completely fine to view or shoot directly, bare-eyed or through any lens.

Why the Moon turns red, not black

Earth’s shadow has two parts: the pale outer penumbra, where sunlight is only partly blocked, and the dark inner umbra, where it’s fully blocked. As the Moon enters the umbra it doesn’t go black — Earth’s atmosphere bends a sliver of sunlight into the shadow, and that light has passed through so much air that the blue wavelengths have scattered away, leaving the deep orange-red that gives a total lunar eclipse its “blood moon” nickname. It’s the same physics as a sunset, refracted all the way around the planet.

The three types

• Penumbral — the Moon only crosses the pale outer shadow. The dimming is subtle, easy to miss without comparing to a normal full moon.
• Partial — part of the Moon’s disc enters the dark umbra; you’ll see a distinct dark, slightly reddened bite taken out of one side.
• Total — the whole disc sits inside the umbra and the “blood moon” colour is unmistakable, sometimes for over an hour.

The exposure jump you need to plan for

This is the one thing that catches people out: a normal full moon is bright enough to shoot at a fast shutter, low ISO, and a moderate aperture — much like photographing a sunlit subject, because that’s exactly what it is. Once totality hits, the Moon is being lit only by the sliver of refracted, reddened sunlight bending through Earth’s atmosphere, and it can be several stops darker. Keep shooting at pre-eclipse settings through totality and you’ll get a black frame.

Re-meter as the eclipse progresses rather than trusting one set of settings for the whole event: lengthen the shutter and/or raise the ISO as the shadow deepens, and check the histogram after each change rather than by eye on a bright screen in a dark sky. A tripod matters more here than for a normal moon shot, since the slower totality shutter speeds are less forgiving of handheld shake.

Framing

A long lens (300 mm+) fills the frame with lunar detail; a standard or wide lens works better if you want the eclipsed Moon set against a landscape foreground. If you want both — a tight lunar close-up and a wide scene-setting shot — plan for two separate frames rather than compromising on one focal length; the Moon is a small, bright disc at any lens shorter than a serious telephoto.

Gear

A tripod (non-negotiable once totality’s slower shutter speeds arrive), a remote release or 2-second timer, and — if you want the tight lunar detail — the longest lens you have.