Solar Eclipses are one of the most astonishing and beautiful astronomical events, that anybody can enjoy if they’re lucky enough to be in the right place, but it is also one of the most dangerous. As the sky darkens and the Sun vanishes behind the Moon, people tend to stare upwards at the view, not realising that there is still enough bright light to damage their eyes, sometimes even blinding them temporarily. This is why astronomers are always so insistent that people either watch the eclipse by means of projection, or through proper filters.
All that heat and light can be just as damaging to a camera, so we need to be just as cautious when photographing the Sun as we are when we look at it. And before we go any further, always remember that a camera viewfinder is a little telescope – NEVER be tempted to use it to frame a shot that includes the Sun! Even if you never look through the viewfinder, it could still project the Sun’s raw image onto your bare skin while composing the shot, leading to painful burns. We recommend taping heavy foil or cardboard over the viewfinder, for safety’s sake.
The safest way to image the Sun is to project its image onto a screen, and point the camera at that. You can project an image with binoculars or a small telescope (AT YOUR OWN RISK, though – all that heat can damage or even shatter lenses inside your telescope!), but the safest and easiest by far is to build a pinhole projector. With this type of photography, any camera will do, from a professional grade DSLR to a simple camera phone. Just point and click!
Neutral Density Filters
If you want to try something a little more advanced, then you can try imaging the Sun directly through a filter. The “Correct” way to do this is to use Neutral Density (ND) filters made to fit your camera – make sure to use a dark enough filter for the task, however. Start with at least a 10 stop filter – it’s better to have it too dark and then open up aperture, than to start too bright and risk damaging your equipment.
If you are using a simpler camera that does not take filters, you can make one yourself from a pair of eclipse glasses (but again, please be careful – if your homemade filter falls off, you might let the full strength of the Sun into your camera or eyes!). Simply take the eclipse viewer, arrange it so that the camera points through one of “eyes”, and use lots of sticky tape to hold it firmly in place. Then turn the screen up to its brightest, shade your eyes against the Sun, and start snapping.
Through a telescope
This is where the serious work happens. If you have access to a proper solar telescope, or an astronomical telescope that has been fitted with purpose built solar filters, then there are several ways to use it to photograph the Sun
IMPORTANT: real solar filters fit over the big end of the telescope. If your filter is small and screws into the eyepiece, smash it with a hammer and bury the pieces where nobody will find them. These little filters get dangerously hot and have been known to shatter unexpectedly, leading to instant eye damage
The simplest way to take photographs through a telescope is called eyepiece projection, and it works best with small, simple cameras. Simply hold the lens up to the telescope eyepiece, and aim through the telescope. Use the screen to find the picture and centre it, then hit the shutter as usual.
If you have a DSLR camera, or a mirrorless camera that allows you to fit different lenses, then you can try Prime Focus shooting: Fit a T-ring adapter to the telescope, which will let you mount it onto the camera as if it were a lens, and start shooting.
Despite the risks of damage and injury, Solar Eclipse photography is very simple if you only want to capture the Sun at one part of the eclipse. But if you want a record of the whole event, you’ll find that both the brightness of the Sun and background light levels vary enormously throughout the event, making it hard to capture consistently good images of the entire event. Our advice to beginners: don’t be a control freak. Modern cameras are very good at selecting the best exposure settings for most shots, and while you might know how to do a better job with the manual settings, you probably won’t be fast enough to keep up with the show and will miss many opportunities for good shots. Just focus on composing your shots and enjoying the show, and let the camera worry the technical stuff.