Easily-made 'pinhole projector' always an option to view solar eclipse

Easily-made 'pinhole projector' always an option to view solar eclipse

August 19th, 2017 by Tim Omarzu in Local Regional News

An LED flashlight is shined through a pair of ISO certified eclipse glasses at full power to show how much light is blocked. It is unsafe to view a solar eclipse using anything but ISO certified eclipse viewing glasses.

Photo by Doug Strickland /Times Free Press.

Total Solar Eclipse coverage

How to make a pinhole camera

You don’t need fancy glasses or equipment to watch one of the sky’s most awesome shows: a solar eclipse. With just a few simple supplies, you can make a pinhole camera that lets you watch a solar eclipse safely and easily from anywhere.

Materials: Two pieces of white card stock, aluminum foil, tape, a pin or paper clip.

Step 1: Cut a square hole into the middle of one of your pieces of card stock.

Step 2: Tape a piece of aluminum foil over the hole.

Step 3: Use your pin or paper clip to poke a small hole in the aluminum foil.

Step 4: Try it out. Place your second piece of card stock on the ground and hold the piece with aluminum foil above it (foil facing up). Stand with the sun behind you and view the projected image on the card stock below. The farther away you hold your camera, the bigger your projected image will be.

Source: NASA


Where in the Chattanooga area can you still get eclipse glasses to safely view Monday afternoon's Great American Eclipse?

Not the Chattanooga Public Library, because on Friday morning, people lined up early and snapped up 100 glasses at each of its four branches (limited to one pair per person) less than 10 minutes after the libraries opened.

"The lines were circled around each branch," library spokeswoman Mary Barnett said.

Not from Elders Ace Hardware, which offered eclipse glasses for $1.99 a pair (limit of four pairs per customer) at a number of its stores Friday morning.

"They were lined up and down the road waiting to get in," said Carl Cantrell, store manager of the Lakesite Ace Hardware, which quickly sold out of 200 pairs. "Believe it or not, we took everybody that was waiting."

Photo by Contributed Photo /Times Free Press.


And not from Allan Jones, the Cleveland, Tenn., multimillionaire founder of Check Into Cash whose charitable foundation donated 43,000 eclipse glasses to students in six area school systems.

"Tell people to quit calling me," Jones said Friday. "I've already given 43,000 away, and I'm out."

However, there was an entrepreneur with 2,000 pairs of paper and film solar eclipse glasses for sale Friday afternoon — for $10 a pair.

East Brainerd resident Keith Shadwick set up shop beneath a blue, pop-up canopy tent in a parking lot on Direct Connection Drive facing Interstate 75 near the I-75 Flea Market close to Exit 1.

Shadwick thinks the $10 price is fair, since he paid $4.85, each, for the American Astronomical Society-approved eclipse glasses that he received Friday morning shipped from England.

"I'm hoping we sell out, but you never know," said Shadwick, whose only advertising was a craigslist posting.

Shadwick's first customer was Gordon Wang, a computer science professor from Cleveland, Ohio, who only decided recently to make the trek to the 70-mile-wide path of totality, or total eclipse, that will sweep across Tennessee, including between Chattanooga and Knoxville.

"I didn't plan," Wang said. "I had no plan two days ago. I decided to come down and spend a few days here."

Another satisfied customer was Dalton, Ga., resident Zach Faulknor, who handed over $40 in cash for four pairs.

"I was just lucky to get them," said Faulknor, adding eclipse glasses prices had soared even higher on Amazon.

Even if you only score one pair of eclipse glasses, they can be shared.

"Every person doesn't have to have one," said Jones, an astronomy buff. "You [can] pass the glasses around and take turns."

Total Solar Eclipse coverage

And there's good news for those who don't find eclipse glasses. A great alternative way to view the eclipse is a pinhole projector, easily made with paper, tape and aluminum foil. It projects an image of the sun that's safe to view — and photograph — since aiming a camera at the sun can destroy it.

Smartphone cameras are less likely to be damaged by a brief photo of the eclipse, NASA says, and Apple says the iPhone will be OK. But NASA warns that a direct glimpse of the sun while taking a smartphone photo could damage your eyes, if you don't have eclipse glasses. And experts say smartphone photos of the eclipse likely won't be very good.

Doctors around the U.S. launched campaigns this summer to warn people that they can damage their eyes staring directly at the sun, even the slimmest sliver of it. They advised people to get special eclipse glasses. The American Astronomical Society put out a list of 15 approved manufacturers.

Complicating the rising demand from last-minute shoppers for eclipse glasses was a recent recall by Amazon that forced libraries and health centers around the country to recall glasses they gave away or sold.

One of the approved manufacturers selling the special glasses, American Paper Optics, has sold 45 million pairs over the last two years — 10 million since mid-July, said John Jerit, president of the Memphis-based company.

Among their customers was Vanderbilt University Medical Center, which had to recall 8,000 glasses purchased from an unidentified third-party vendor and given out at a county fair last weekend. The center was offering people the chance to exchange the faulty glasses for new, certified ones from American Paper Optics Friday through Monday.

The Associated Press contributed to this report.

Contact staff writer Tim Omarzu at tomarzu@timesfreepress.com or www.facebook.com/MeetsForBusiness or on Twitter @meetforbusiness or 423-757-6651.