Capturing the 2017 total solar eclipse
On Monday, August 21, 2017 there will be rare celestial event visible in the United States: A total solar eclipse. The umbra, or the deepest shadow cast by the moon completely blocking out the light of the sun will trace a band across 14 states from Oregon to South Carolina. The eclipse will also be partially visible everywhere in North America, northern parts of South America and in some parts of Western Europe and Africa.
For photographers this is an opportunity to take some stunning shots but it will take some preparation. Even in the center of the totality band the total eclipse will only last two and a half minutes as the shadow of the moon crosses the surface of the earth thousands of kilometers per hour.
So, to prepare for this event, begin by sorting out your gear first. You will at least need the following things: A tripod, a DSLR camera (with full battery and empty memory card) and a suitable lens. If you wish to capture anything else besides the total eclipse you must also have a solar filter (a high ND number neutral density filter) for the lens. Never point your camera at the sun without a proper filter or you may damage it permanently! You can also use a point-and-shoot camera or a mobile phone to capture the event, just adjust the guide accordingly and keep in mind the limiting factors like lack of a filter and the focal length.
If possible, test out your camera settings in advance on an un-eclipsed midday sun. Set your camera on a tripod and attach the solar filter on your lens. Set your camera to manual mode and set your ISO sensitivity to lowest setting (usually 100). Set your aperture small, something between f/8 and f/16. Set shutter speed to fastest setting, 1/4000 or whatever your camera allows. Change to manual focus and focus your camera to infinity, then point your camera at the sun. Make a few test exposures and change shutter speed to slower setting if needed. Make sure the image is sharp and that check from the histogram that the exposure is correct, not under- or overexposed. Capture raw images if possible. Try bracketing to make sure you get the perfect exposure. Keep also in mind that the sun moves fast so you will need to track it across the sky.
Then prepare for the actual eclipse: Find out where the totality band will be and figure out how to get there. You will probably want to be in the very center of the band where the totality lasts the longest. NASA has excellent maps showing where the umbra will fall and various app stores have different applications for the same purpose. Check when the eclipse will begin and be on the location on time.
During the eclipse there are four moments you will need to pay attention to. These moments are called C1, C2, C3 and C4. C1 is the beginning of the eclipse, when the disc of the moon just crosses the disc of the sun. C2 is the moment just before the disc of the moon blocks out the disc of the sun, C3 the moment when the disc of the sun just comes visible again and C4 when the moon passes the sun completely, ending the eclipse. At C2 and C3 you can capture the "diamond ring" formed by the sun just barely visible from behind the moon. Between C2 and C3 (and only between C2 and C3) these times you can your eye protection and look at the sun with naked eye and try to capture the corona of the sun with your camera. To properly do this you will need to remove the solar filter and adjust your camera settings as the corona is much fainter than the sun's photosphere. Remember to put your filter and eye protection back before the sun becomes visible again and change your camera settings again.
With these instructions you should be prepared to capture the sun during the eclipse. But also try capturing the people around you during the eclipse, make a stunning landscape shot under the umbra or see if you can catch the elusive shadow bands. But also enjoy the moment and don’t just stare at your viewfinder.