Eclipse News

Viewing the Total Eclipse: Indirect Methods

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There are several ways to safely view the sun during the eclipse, as an individual or in a group.  Before we delve into those options we need to state the rule that is never to be broken, or even bent.  NEVER look at the sun directly without proper eye protection.  Directly includes binoculars, cameras, telescopes and eyeballs.  No exceptions.

Except one – during totality.  For the two and one half minutes of the Big Show, glasses come off faces and filters are removed from lenses to look upon a sun now completely blocked by the moon, revealed only by its otherwise invisible corona.  As the solar glare reemerges glasses are replaced and filters are secured.

Projection Protection

By far the safest way to view the eclipse is to not look at it directly at all.  The most basic method of projection is the simple pinhole, which will project an inverted image of the object onto a surface.  During the partial eclipse overlay your hands at right angles such that the spaces between your fingers form holes and project images of the eclipse on the ground, or better yet onto a piece of white cardboard.  Stand next to a tree and look at the ground beneath it during the eclipse and you will see multiple sun crescents on the ground, the tree and the spaces between the leaves causing the effect as light filters through the tree.  Crazy.

There are many resources on the web for constructing pinhole devices, from a couple of pieces of cardboard to more elaborate box designs made of basic materials (cardboard, tape, scissors, aluminum foil).  In principle, the smaller the whole the sharper the image and the longer the box the larger the image, however, both of these modifications make the projection dimmer.  Like a telescope or camera you are modifying the aperture or focal length and increasing the f/stop of the system.

 

NASA site with simple DIY projector

Time and Date has a wealth of info, here is a simple DIY box projector

 

Another great site with videos; check out the DIY long box projector

DIY Photography site with creative pinhole cameras

 

Being able to magnify the object with binoculars or small telescopes prior to projection is obviously a step up in quality from the simple pinhole.  A sturdy tripod or mount is essential to steady the image and ease focusing, as well as a white surface (cardboard, screen) on which to project your image.  Care must be taken when initially aligning the optical device (look at the shadow of your device on the ground and move it until it is at its smallest) and NEVER look through the device when aligning.  Oops, I did it again.

Check out the Exploratorium site for a bino setup and Sky and Telescope for information on using small telescopes.

Our last Projection Protection Device is a nifty little number this dawg constructed for the transit of Venus in 2012, the year the world did not end.  Missed the transit?  No worries, catch the next one in 102 years.  The Sun Funnel is easy to construct and produces a large, sharp image of the sun projected through a small telescope.  You will need an eyepiece, I used an older stock model that came with one of my scopes, a large oil funnel, a couple of hose clamps, and a piece of projection screen (google it).  It’s the cat’s pajamas.  Head over to Dave Reneke’s World of Space and Astronomy for a detailed plans.

 

 

Dark Room

Before signing off let’s take a moment to appreciate the camera obscura, a fascinating device based on pinhole projection.  Known to ancient Chinese and Greek writers, the camera obscura has been used and studied ever since.  When a lens and photographic film was added, the first box camera was born.  Here is the Wikipedia entry, full of information on the principle behind and history of the camera obscura.

Modern artists using modern equipment have taken the dark room with a pinhole in the window shade to new heights.  My favorite is the work of Abelardo Morell, whose art has been exhibited in museums around the world.  His stunning images using camera obscura, including a series taken inside a darkened tent, complete the “marriage of the outside with the inside”.  The images below are from his website.

© 2017 Abelardo Morell

 

And the moon in haste eclipsed her,

And the sun in anger swore, 

He would curl his wick within him,

And give light to you no more.

Aristophanese, Chorus of Clouds, 423 BC

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