How to photograph a solar eclipse

A solar eclipse happens when the Moon passes directly between Earth and the Sun. Depending on the alignment and the Moon’s distance that day, you get one of three coverage types, and the safety rule changes with it.

The non-negotiable rule: a certified solar filter, always

Never point a lens — or your eyes — at the Sun without a certified solar filter. The Sun’s direct light will burn a sensor and permanently damage your eyes in seconds, eclipse or not; a pair of ordinary sunglasses or a stacked ND filter does not make it safe. Use a filter certified to the ISO 12312-2 standard (the same rating eclipse-viewing glasses carry), fitted over the front of the lens before you ever point it at the Sun. Check it for scratches or pinholes before every use — a damaged filter is not a safe filter.

The one exception is the brief window of totality in a total eclipse (below) — and only totality, never the partial phases either side of it.

The three coverage types

• Partial — the Moon takes a bite out of the Sun’s disc but never fully covers it. The filter stays on the whole time. This is what you see from outside the path of a total eclipse, or throughout an entire partial-only eclipse.
• Total — the Moon fully covers the Sun for a few minutes, and only during those minutes is it safe to remove the filter: the Sun’s faint outer atmosphere, the corona, becomes visible as a pale ring. The instant a sliver of the Sun’s disc reappears (“diamond ring”), the filter goes back on immediately.
• Annular — the Moon is far enough from Earth that its disc is too small to fully cover the Sun, leaving a bright “ring of fire” at maximum coverage. Unlike totality, the Sun’s disc is never fully blocked, so the filter stays on throughout, even at maximum eclipse.

Settings by phase

With the filter on, meter normally through it — it cuts the light so heavily that ordinary daylight settings (a mid aperture, a fast-ish shutter, base ISO) will be close, then fine-tune from the histogram. A longer lens (300 mm+) fills more of the frame with the Sun’s disc; a tripod and remote release keep the framing steady as you track the Sun’s slow drift across the sky.

The moment totality begins and the filter comes off, the light drops dramatically — you’re now photographing the corona, not the filtered Sun, so re-meter from scratch: a much slower shutter and/or higher ISO, and consider bracketing a spread of exposures, since the corona’s brightness fades gradually from the bright inner ring to the faint outer streamers and no single exposure captures all of it.

Gear

A certified (ISO 12312-2) solar filter sized to your lens, a telephoto lens, a sturdy tripod, and a remote release or 2-second timer. For totality, a lens hood helps block stray light as the sky darkens around you.