Best advice for most hoping to photograph the eclipse: Don't
Posted August 5
This will be the most photographed eclipse ever. Your chances of getting results that come close to the amazing images captured by professionals and serious amateurs that will begin flooding Flickr, Facebook and Twitter the afternoon of August 21 are slim, especially with a smartphone.
Why? The moon is small and the sun is bright, making the pair difficult to photograph.
The sun and moon appear about half a degree in diameter in the sky (there are 180 degrees from horizon to horizon). For comparison, hold your outstretched hand to the sky. You can cover the sun and moon with your pinky finger, twice.
The camera on your smartphone captures between 50 and 75 degrees of the scene in front of it. You could fit 100 to 150 eclipses in there. Zooming in won't help because this is likely performed digitally by your phone, meaning pixels at the edges are being thrown away and the image is then simply enlarged without any improvement in quality.
Unfiltered sunlight, even when 93% obscured here in Raleigh, will appear as shapeless blown out pixels in the resulting photo.
While your smartphone or other point and shoot camera just aren't up to the task of directly photographing the eclipse, they are great for indirectly capturing the eclipse and its effects.
Don't rely on auto focus and exposure. In the reduced ambient light, you may have to do it manually. Tap the screen and hold to lock focus. Then slide your finger up or down to darken or lighten the exposure until you see details in the image.
If you have an unobstructed view of the northwestern horizon, look for the lunar shadow racing toward you a few seconds before totality.
Weather you are in totality or not, try a time-lapse of the scene around you as it darkens and then returns to daylight.
Whether shooting with a smartphone or a professional DSLR camera, a timer or shutter release helps provide sharper, vibration-free images.
During partial phases of the eclipse, look for hundreds of little eclipses to be projected onto the ground by light streaming through trees. Also be sure to get photos of friends and family experiencing the event as they look silly wearing eclipse glasses. These are the images you’ll want to remember. There will be plenty of expertly created photos of the eclipse itself available to add to your photo album after the event.
Also, turn off the flash. It won't make your photo any better and will spoil the show for everyone else.
If you are still intent on photographing the eclipse itself with your DSLR, a little homework will not only help you get the best photos possible, but ensure you have time left to experience the event as well. The 2.5 minutes of totality is not the time to experiment.
The most important thing to remember in photographing the eclipse is that you are still photographing the sun and need to prepare your camera appropriately. Never look through the viewfinder of a camera pointed at the sun without a solar filter in place.
You might have come across online tutorials that suggest using neutral density filters for photographing the eclipse. Some filter manufacturers market 16-stop filters for solar photography but Canon, Nikon, and NASA all recommend against them. Instead, use ISO certified solar filters which block sufficient visible light as well as hazardous infrared and ultraviolet light beyond 800 nanometers.
Not all solar filters are the same. Some are safe only for photography, others are safe for viewing the eclipse through the viewfinder. Be safe and use the live view function on your camera’s LCD screen.
When selecting a lens, keep in mind the moon and the sun are smaller in the sky than you might realize. The 18-55mm kit lens that came with your DSLR camera will make the eclipse appear as a speck in the sky, only marginally better than a snapshot form an iPhone.
The American Astronomical Society recommends at least a 300mm telephoto lens and even then you can fit more than 8 eclipses across that field of view. If you’ll be photographing from the path of totality, a 1000mm or longer lens is recommended to capture details such as Baily’s Beads, prominence and flashes of color in the inner corona.
Light changes quickly throughout the eclipse, making the selection of aperture and shutter speed challenging. Astronomer Xavier Jubier created an interactive shutter speed calculator for solar eclipses. Most of North and South Carolina can use 66 degrees for the altitude of the sun and 100 meters for the elevation of the observer to calculate. Adjust ISO as low as possible to support the calculated shutter speeds.
Write down your planned aperture and shutter speed settings for the big day, and take moment to put these in your camera bag. If you plan to shoot the eclipse directly, pre-focus your camera on the moon tonight and tape down the lenses.
There is as much as a 12-stop difference across the inner and outer portions of the corona and exposure bracketing will provide the choices you’ll need later. In an article in Outdoor Photographer magazine, Lewis Kemper recommends bracketing to give the widest possible dynamic range to chose from. Prosumer camera owners limited to 3 auto-exposure bracketing (AEB) frames should set those to +/- 2 stops and take three shots each at -5, 0, and +5. You’ll get the same 14-stop dynamic range as the pros and their 7 AEB frame cameras.
Don't forget to pack a tripod and a remote shutter release. Your subject is 238,900 miles away. Even the motion of depressing the shutter can ruin an otherwise good photo. Also, bring some small white washcloths or handkerchiefs to drape over your camera to prevent overheating.
Finally, test everything with solar filters in place a few times at twilight between now and August 21. Those 2.5 minutes will go by too quickly. Properly prepared you’ll have time to capture memorable photographs and enjoy the unforgettable experience of a total solar eclipse. Be sure to share your photos with WRAL.
Tony Rice is a volunteer in the NASA/JPL Solar System Ambassador program and software engineer at Cisco Systems. You can follow him on twitter @rtphokie.