Capturing the wonders of the night sky is hugely enjoyable and rewarding, and you don't need specialist equipment to produce high quality images. Drew Buckley shares his advice on how to photograph our own galaxy, the Milky Way
There's something totally hypnotic and mesmerising about gazing out and up at objects that are billions of years old and light years away. With technology advancing all the time, and camera sensor performance better than ever, we no longer have to leave all the fun to expert astronomers. Anyone can photograph the night sky, and the most impressive and easiest celestial subject to capture is the Milky Way, the galaxy that contains our solar system.
Thanks to the internet we have a wealth of information at our fingertips, and this can be particularly useful when it comes to navigational aids and planning resources for astrophotography. My favourite app for desktop and mobile devices is Stellarium (stellarium.org). I've been using it for years now and it's so useful for finding out where the Milky Way will be on a certain date, and at an exact time; it's a vital tool in helping to line up the sky with an interesting foreground. Also check out the PhotoPills app (photopills.com) for location planning and, to find dark sky areas near you, visit lightpollutionmap.info.
As our solar system is within the Milky Way, when we are gazing up at its stars we are looking from one of the arms our own galaxy. The centre of the Milky Way that is most clearly seen by the naked eye isn't visible all year round, especially for those of us living in the northern hemisphere; the optimal time for photography for us is between April and September. Here's how you can capture a shot of the Milky Way for yourself.
- Don't just head to any location at night; you really need to find a dark place away from light pollution. Also, choose a day when there's a new moon, because too much illumination can ‘wash out' a starry sky.
- You'll find the galactic core (the rotational centre of the Milky Way) in a southerly direct ion in the night sky, and it will travel west as the night progresses. The angle at which it's tilted changes too. Early in the year the Milky Way will appear at a 45° angle when it rises; in late summer it will rise almost vertically.
- A digital camera with high ISO capabilities will allow you to capture lots more information in low-light situations. Switch it to manual mode too, so that you can take complete control of the settings.
- Choose a lens with a maximum aperture of at least f/2.8 - the faster the better. Also, the wider the field of view, the more sky you can capture. With Milky Way images, you'll always be using shutter speeds in the 20 to 30-second range, so you really need a good, solid tripod to create sharp images.
- I recommend using live view to set up your shots: magnify your screen and manually focus on the stars themselves. This way they will come out pin-sharp.
Above Long-exposure image looking into the galactic core of the Milky Way, taken on the south Pembrokeshire coast line.
- Once you've set up, it's time to dial in the settings. The reason for using a wide lens (mentioned previously) is not only to capture a wider field of view; it also gives a yardstick for choosing the right shutter speed. Although we can't feel it, our planet rotates on its axis one revolution per day. As such, when we shoot long exposures at night, the motion becomes visible by the trailing of the stars. This effect is ideal for star trail photography, but for Milky Way imagery we want the stars to be rendered as neat dots, not streaking lines. You'll always need to use your lens at its widest aperture for maximum light intake.
- To capture pin-sharp stars, use the ‘500 rule': divide 500 by the focal length of the lens you're using - this will give you the best shutter speed to combat star trailing. For example, a 24mm lens on a full-frame camera results in a 20-second exposure (500÷24 = 20.83). Remember to adjust this if you're using a crop-sensor camera, multiplying the focal length by your crop factor.
- With aperture and shutter speed set in stone, all that's left is the ISO. In astrophotography ISO is your best friend, and I'd always opt for increased sensitivity, rather than worrying about noise. The difference in image quality can be marginal, and there's some great noise reduction software available. Start with ISO 1600 and check how the image looks by reviewing it on your LCD. Most of the time I'll be shooting at around ISO 3200, but I have captured some successful results at ISO 6400 and up. All camera sensors are different in how they handle high ISO noise, so choose the right speed depending on what best suits your camera.
- With all the techy stuff dialled in, it's time to get creative! How you capture your images will be down to your own ideas, but I'd recommend starting with prominent landmarks or interesting landscapes to incorporate into your composition. You can even stand in front of the camera for a mega selfportrait. Astrophotography is a form of landscape photography, so having a killer foreground to accompany an amazing star-filled sky can add real impact to your images.