Eclipse Watching Preparation Checklist

ISO 12312-2 certified eclipse glasses must block at least 99.999 percent of visible light, reaching an optical density of 5 or higher, along with essentially all ultraviolet and infrared radiation, and that single number is the difference between safely watching a partial eclipse and risking permanent retinal damage.

The next total solar eclipse crosses Europe, North Africa, and the Middle East on August 2, 2027, with totality visible from parts of Spain, Morocco, Algeria, Libya, Egypt, and Saudi Arabia. Wherever you plan to watch a future eclipse, whether that one or a partial eclipse visible from your own backyard, the preparation checklist is largely the same, and most of the mistakes that ruin an eclipse day are avoidable with a few weeks of planning rather than a few hours.

Eye Safety Comes First, Always

The only time it is safe to look at the Sun without a certified solar filter is during the brief period of total eclipse totality itself, when the Moon completely covers the Sun's disk, a window that at most eclipses lasts somewhere between one and four minutes. Outside that narrow window, even when 99 percent of the Sun's disk is covered by the Moon during a partial or near-total phase, the remaining sliver is still bright enough to cause retinal burns within seconds, because the retina itself has no pain receptors to warn you.

• Check for the ISO 12312-2 mark printed directly on the eclipse glasses or solar viewer, along with the manufacturer name and a certification statement, not just a generic "safe for solar viewing" claim.
• Inspect the filter material for scratches, punctures, or wrinkles before each use; even a pinhole-sized flaw can let through enough concentrated sunlight to cause damage.
• Never look through a camera, telescope, or binoculars using only eclipse glasses. Optical instruments concentrate sunlight far beyond what eclipse glasses are rated to handle; these need their own certified solar filters mounted over the front aperture, not held up to your eye.
• Supervise children closely. Kids often lift glasses to peek or fail to keep them centered over both eyes; an adult should check positioning every few minutes.

The Photography Filter Is a Different Product

ISO 12312-2 is written specifically for direct, unaided-eye solar viewing products like eclipse glasses and handheld solar viewers. It does not apply to solar filters intended for telescopes, binoculars, or cameras, which require their own dedicated full-aperture solar filters designed to handle the concentrated, focused light passing through the optics, not just naked-eye brightness.

Building Your Eclipse Day Gear List

Indirect Viewing Methods, No Filter Required

A pinhole projector turns the Sun's own image into a safe, filter-free viewing method by letting sunlight pass through a small hole in a card and projecting a tiny inverted image of the Sun onto a second surface held below it. This works because you never look at the Sun directly, only at its projected image. A kitchen colander produces the same effect through dozens of small holes at once, projecting a field of small crescent-shaped Sun images onto the ground during a partial eclipse, a genuinely popular and effective low-cost method.

If You Are Traveling to the Path of Totality

Totality itself, when the Moon fully covers the Sun's disk, is the only phase where it is safe to remove eclipse glasses entirely, but only for the exact duration of totality at your specific location, which can range from under a minute to over four minutes depending on where along the path you stand. Traffic near popular viewing locations along a path of totality routinely backs up for hours both before and after the event, since a narrow band of land, often just 100 to 200 kilometers wide, suddenly draws visitors from a much wider surrounding region.

• Arrive the day before if possible, rather than driving in the morning of the eclipse; post-eclipse traffic leaving the path of totality is often worse than the arrival.
• Check the specific local timing for your viewing spot, not just the general date, since first contact, totality, and last contact times shift by minutes depending on your exact longitude within the path.
• Have a cloud backup plan. Weather forecasts for a specific location and date months out are unreliable; scouting two or three potential viewing spots within driving distance, with different cloud cover odds, hedges against a local overcast sky ruining the one shot you traveled for.

A Final Pre-Eclipse Checklist

A week before any eclipse you plan to observe, confirm your glasses show no visible damage when held up to a bright household lamp, indoors, well before eclipse day, since a pinhole that lets through lamp light will also let through dangerous solar radiation. Confirm any telescope or camera solar filter is securely attached and cannot slip or fall off during use. Print a physical copy of your local eclipse timeline in case of network congestion, and if you are watching with children or a group, walk through the safety rules out loud before the eclipse begins, not during it, when excitement and instructions tend to compete for attention.

Partial and Annular Eclipses Happen Far More Often

Total solar eclipses grab the headlines, but partial and annular eclipses, where the Moon covers only part of the Sun's disk or leaves a bright ring visible around a centered Moon, occur more frequently and are visible from a much wider area than the narrow path of totality. An annular eclipse happens when the Moon is near the farthest point in its elliptical orbit from Earth, appearing slightly too small to fully cover the Sun's disk, leaving a bright ring, sometimes called a ring of fire, around its edge.

Checking which type of eclipse is visible from your specific location before eclipse day, rather than assuming any solar eclipse means a chance to safely view totality, prevents the most common and most dangerous mix-up in eclipse planning.

Photographing an Eclipse Without Ruining Your Equipment

Pointing an unfiltered camera lens or telephoto lens directly at the Sun, even briefly to frame a shot, can permanently damage a camera sensor through concentrated heat, the same risk a magnifying glass poses to a piece of paper on a sunny day, except focused onto delicate electronics instead. A properly rated full-aperture solar filter over the front of the lens is required for the entire partial phase, removed only during totality if you are within the path and photographing that specific brief window.

Because totality lasts at most a few minutes, rehearsing your camera settings, filter removal and reattachment, and framing well in advance, ideally with a full practice run days beforehand, matters far more than any single piece of gear; observers who spend their few minutes of totality fumbling with settings routinely report wishing they had simply watched instead.