How to safely watch a solar eclipse
It’s not just eyes that are an issue. Cameras are at risk if you try to photograph this astronomical wonder without a filter.
Cameras, in a sense, are gigantic magnifying glasses. That’s great when you attach a telephoto lens to a camera to photograph an eagle. But it can hurt your eyes and your camera if you’re shooting the sun.
Never look at the sun through the viewfinder without a filter. That goes for all times during a partial eclipse and with all types of lenses.
It’s safe to view the sun unprotected only during totality, when it’s completely blocked by the moon.
According to NASA’s photo tips page: “If you ONLY take a photo at the moment of totality, you will not need (a solar) filter, and will be rewarded by being able to photograph the faint corona, which will not be visible if you have the filter in place.
“Most digital cameras with telephoto lenses of 100mm or larger will show a disk for the eclipse that will show some detail.”
The other exception for going filterless on your camera is for quick exposures, 1/4000 of a second, for instance. But protect your eyes, even for a glance.
The rest of the time you’ll need a filter over your camera lens — the same kind used by eclipse watchers. Otherwise, you’ll risk burning out the digital sensor if you expose it to the sun without a filter.
Finding one big enough to cover your camera lens may be difficult at this point. No. 14 welder’s glass will do the trick, so this might be the time to hit up your welder friends.
Ohio Wesleyan University’s Perkins Observatory, on its website, adds this caution: “No stacking! A pair of No. 7’s or a 10 and a 4 together do not have the same protection as a single piece of No. 14.”
As for smartphones, NASA says on its website: “There is no valid reason why you would want to point your smartphone camera at the brilliant, uneclipsed sun without putting a filter over the lens.”
Videos are another matter, given the length of time the equipment is pointed at the sun to record.
During an experiment, a News Tribune staffer quickly burned a hole in a filter he’d improvised from mylar eclipse glasses placed in front of the camera’s sensor and behind the lens.
The lens acted as a magnifying glass when he pointed the camera at the sun.
“During the partial phases, shoot three-to-five-second clips of the sun every four to five minutes to produce a time-lapse sequence that will compress the multihour event into minutes,” advises the American Astronomical Society. More details can be found at its tips page: bit.ly/2wgtLod.
As Nikon’s eclipse photography tips page notes, you need a solar filter for shooting not only for your eyesight but also “to keep from harming your camera’s imaging sensor as well as for correct exposure.”
A quick search Wednesday on Amazon showed different vendors sold out of solar filter sheets for telescopes and cameras.
Because at this point solar filters for your gear might be as hard to find as eclipse glasses, NASA offers this suggestion to keep things simple:
“Use a kitchen sieve or colander and allow its shadow to fall on a piece of white cardboard placed several feet away. The holes in the utensil act like pinhole cameras and each one projects its own image of the sun.
“The effect can also be duplicated by forming a small aperture with one’s hands and watching the ground below. The pinhole camera effect becomes more prominent with increasing eclipse magnitude.
“Virtually any camera can be used to photograph the phenomenon, but automatic cameras must have their flashes turned off since this would otherwise obliterate the pinhole images.”
The American Astronomical Society also offers tips on its page for telescope or binocular projection for safe eclipse viewing at eclipse.aas.org/eye-safety/projection
The Washington Post also offers a step-by-step guide to take smartphone photos of the event safely at wapo.st/2uJb0Ks
At this point, with the sellout of eclipse eyewear in the area and solar filters on Amazon, one could argue to just go old-school and take pictures with your mind.