How to photograph a solar eclipse :: Digital Photo Secrets

How to photograph a solar eclipse

by David Peterson 1 comment

There was a time when a solar eclipse was considered a bad thing. The ancient Greeks believed that solar eclipses only happened when the gods were angry, and that natural disasters and general destruction were not far behind. The Vikings believed that when an eclipse happened, it was because hungry wolves were eating the sun. And in many cultures, a solar eclipse was said to portend death—King Louis the Pious died shortly after witnessing a solar eclipse, believing that it was a sign of God's displeasure.

Today, of course, solar eclipses are just cool photography subjects. And they’re easy to photograph, too, provided you have the right equipment and a little bit of know-how. Keep reading to learn more.

[ Interested in photographing the Great American Eclipse on Aug 21? Learn specifics and tips for this unique event here ]

Safety

Now, I'm sure you remember all of the warnings against looking at a solar eclipse with your bare eye (remember those pinhole projectors you made as a kid out of two pieces of cardboard?) That wasn't just your mom being paranoid, there is actually a certain amount of danger associated with viewing a solar eclipse. While you don't usually look directly at the sun, a solar eclipse is like a train wreck, at least in the sense that if you know it's there you're going to have a hard time stopping yourself from staring at it. And you may be lulled into a false sense of security, believing that because most of the sun's light is blocked it must be safe to look at, when in fact the opposite is true—because the light from the sun remains constant throughout the early phases of the eclipse, it is actually focused light, which means that looking at it is a little bit like being the bug under mean a kid’s magnifying glass on a summer day.

Although it is safe to look at the total eclipse with your bare eye, in the phases leading up to that moment, you need to take precautions. Even when 1 percent of the sun's surface is still visible, looking directly at the eclipse can cause permanent eye damage—whether you're looking at it with your bare eye, through your camera's viewfinder or through a telescope. That one percent of the sun is still 10,000 times brighter than the full moon, so keep that in mind while you're preparing to shoot photographs of the event.

  • Sony SLT-A77V
  • 50
  • f/14.0
  • 0.013 sec (1/80)
  • 45 mm

Sutro Tower: Solar Eclipse 2012 by Flickr user trophygeek

Camera and equipment

The pinhole projector method is a great way to observe a solar eclipse, but that doesn't help you a whole lot if your goal is to photograph the event. What you need is a solar filter, which is basically just a very dark neutral density filter. Depending on the make and model, a solar filter will block between 14 and 17 stops of light—as an example, the Marumi solar filter blocks 16.5 stops, which means only about 1/100,000 of the sun's light reaches your camera's sensor. Just remember that if you're shooting the sun with a DSLR, you can safely look through your camera's viewfinder at the solar eclipse provided the filter is attached—but if your camera's viewfinder views the scene separately from the lens, it's not going to be safe to use as a tool for viewing an eclipse. Use live view instead, or use that simple cardboard pinhole projector to view the eclipse and your camera to photograph it. (You can also buy eclipse sunglasses, which are ND filters for your eyes—these are great tools for viewing an eclipse without having to rely on cardboard.)

You can really use any camera to photograph a solar eclipse, provided that it can be fitted with a solar filter. If it can't, you might be stuck with taking pictures of that piece of cardboard with the image projected on it, which let's face it makes for a pretty dull image. Now even a standard 50mm prime lens can get a shot of a solar eclipse, but the sun is going to be a pretty tiny percentage of the frame—so the longer your focal length, the better. And remember that your camera's resolution plays a role as well—make sure you're using every last megapixel because you may find that you need to zoom and crop your image, and you don't want to end up losing so much resolution that you can't print the final image. Switch to RAW format if your camera gives you that option (in RAW, your camera will capture the maximum amount of detail and resolution it's capable of). If you can't shoot in RAW, make sure to select "Fine" quality.

Adding a teleconverter is a great way to capture a larger image—a 2x teleconverter will turn your 400mm lens into an 80mm lens, which should be enough to capture some really spectacular detail, especially if you're shooting at maximum resolution.

One final piece of equipment that you need for photographing a solar eclipse (especially when it becomes a total solar eclipse) is a tripod. It's a good idea to mount your camera on a tripod prior to the start of the eclipse, then (with your solar filter in place) frame the sun, lock focus and wait for the event to begin. Keep in mind that you will need to make minor adjustments as the sun moves through the sky, but having your camera mounted on a tripod will really help take some of the hassle out of the process, especially when you are shooting the total eclipse and it will be necessary to take bracketed shots for combining in post-processing (more on that in a minute).


Solar Eclipse by Flickr user blachswan

Use a remote release—you'll be using slower shutter speeds during the total eclipse and you don't want to add any camera shake to your photos. And because time is really important for solar eclipse photography (at best, the totality only lasts a couple of minutes), don't rely on your camera's self-timer—you don't want to miss shots because you're waiting for your camera to count down.

Settings

The funny thing about eclipses is this: even though the sun is partially blocked, its brightness remains constant until it gets to the "narrow crescent" phases of the eclipse. So this means that you can take test shots of the sun before the eclipse, which will help you determine what settings to use during the event itself.

You can't really trust your meter when your camera is pointed directly at the sun, so the best approach is to select a low ISO (even with that solar filter, ISOs between 100 and 400 are going to be adequate for photographing the sun because the sun is really the brightest light visible on planet Earth) and take a series of test images, starting at f/8 and moving up to f/16 or f/22. Use your histogram to determine which of these exposures is the best one. Note that if the weather changes between the time you took these test shots and the time of the eclipse, you may have to add some exposure compensation.

Use manual focus—the sun is a distant object, so one you’ve locked onto it you’re not going to need to refocus at any point during the eclipse. And you don’t want your autofocus doing that annoying hunting behavior after you got the focus locked, because it will mean having to start over again. The most efficient way to focus on the solar eclipse is to do it one time, switch to manual focus and leave it exactly where it is.

Shooting the eclipse as it progresses is the easy part—until the eclipse reaches those "narrow crescent" phases, you can continue to use the same settings you used for your test photos. During the narrow present phases, add an exposure compensation of +2. But the real trick is capturing the total eclipse, which lasts for only a few moments. During the total eclipse, the sun's corona (its outermost atmosphere) is visible around the edges of that black disc. The corona is only about as bright as the full moon, so not only is it safe to look at without a solar filter, but it is also necessary to photograph it without the solar filter because the filter would block out all or most of that relatively faint light. With enough magnification, the sun's red prominences will also be visible—those are bright, gaseous loops that rise from the sun's surface, extending outwards into the corona. Just below the corona is the chromosphere, the rosy-red inner layer of the sun's atmosphere, which is only visible during a solar eclipse.


    The Sun's corona during the 2006 Total Solar Eclipse by Flickr user the_exploratorium

    Now because you have to move fast, you should walk through the steps for photographing the total eclipse well in advance of the event. First, make sure you remove the solar filter. Because the brightness of the corona is so variable (the outer corona is much dimmer than the inner corona), you need to bracket your shots in order to capture the full range of brightness. Use the same f/stop you chose for the partial eclipse, but bracket your shutter speed, starting with 1/1000 and working your way down to a full second. Be aware that the total eclipse isn’t going to last long, and make sure you’re ready with your solar filter as soon as the sun starts to break away from that shadow. You don’t want to be caught looking at the eclipse or pointing your camera at it after totality because you could damage your eyes or your camera.

    Post-processing

    You’ll get the most brilliant images of the total eclipse if you combine exposures in post-processing. You can do this with the built-in HDR features of software like Adobe Photoshop, or you can use dedicated HDR software like Photomatix. Just be aware that HDR software may give your photos a bizarre and surrealistic appearance, so unless that’s what you’re going for, choose more photorealistic presets.

    Conclusion

    Solar eclipses are fun and exciting events, and you do have some time to capture them so there’s no need to go into panic mode once that much-anticipated event begins. There are several factors that determine the length of an eclipse—the distance between the moon and the Earth (the moon orbits elliptically, so its distance from the Earth is not constant), the distance between the Earth and the sun and whether or not the eclipse is partial or total. But generally speaking, an eclipse lasts a couple of hours from its beginning to end, with the total eclipse lasting a couple of minutes, so you have some time to experiment, play with that pinhole projector and enjoy the experience.

    Summary:

    1. Safety
      • Use a pinhole projector to view the eclipse
      • Use a solar filter to protect your camera
    2. Camera and equipment
      • Use a longer focal length
      • Switch to RAW
      • Add a teleconverter to extend your focal length
      • Use a tripod and remote release
    3. Settings
      • Use a low ISO
      • Take a series of test shots between f/8 and f/22
      • Use manual focus
      • Add +2 exposure compensation in the narrow crescent phases
      • Remove your solar filter for the totality
      • Take a series of bracketed shots between 1/1000 and 1 second
      • Replace the solar filter after the totality ends
    4. Post-processing
      • Use HDR capable software to combine images

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    Comments

    1. Mark Bonacic says:

      You may want to mention turn off image stabilization for shots taken with a tripod

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    Difficulty:
    Beginner
    Length:
    15 minutes
    About David Peterson
    David Peterson is the creator of Digital Photo Secrets, and the Photography Dash and loves teaching photography to fellow photographers all around the world. You can follow him on Twitter at @dphotosecrets or on Google+.