During the evening of 27-28 September, millions of people across North and South America, Europe, western parts of Asia and North Africa were able to witness the phenomenon popularly known as the ‘Blood Moon’. The following morning, social media sites were filled with photographs taken by members of the public who stayed up to the early hours (and were blessed with clear skies) to see what was, in fact, a total lunar eclipse.
During a total lunar eclipse, the moon takes on a reddish colour. Although lunar eclipses are fairly common – a minimum of four total or partial eclipses happen every year – the total eclipse on 27-28 September was of a ‘supermoon’, and is a much rarer event. According to NASA, such eclipses occurred only five times in the 1900s – in 1910, 1928, 1946, 1964 and 1982. The total eclipse of the most recent supermoon was the first one of the 21st century and will not happen again for another 18 years.
But what is a supermoon? Simply, it is phrase given to a full moon that is closest to the Earth. When rising above the horizon, a supermoon can look larger and brighter than a typical full moon. Therefore the blood red hue of a supermoon in total eclipse will make a dramatic impression on the night sky, as the pictures of last September proved.
Low light capability
Not so long ago, taking a photograph of a lunar eclipse (or of the stars and the moon on any clear night), was regarded as the niche preserve of a well-equipped astronomer or astro-photographer. That is no longer the case, as modern cameras now possess extraordinary low light capabilities making it possible for anyone to photograph galaxies and constellations hundreds of light years away.
The breakthrough camera launch that made this possible was the Nikon D3 in 2007. Not only was it the first DSLR camera to use a ‘full frame’ (35mm format sensor), but it enabled photographers for the first time to make finely detailed exposures at night at ISO settings of 6400 or higher. Suddenly, low light and night-time exposures became far more accessible. Although Nikon’s top of the range camera at the time – and with a premium price to match – it wasn’t long before this sensor technology and high ISO capability found its way into more affordable cameras. Now, pretty much any digital camera can deliver incredibly fine resolution images at ISO 6400, 12,800 or even more. But even with this tech at your fingertips, there is still more to shooting a Blood Moon or the Milky Way than pointing your camera in the right direction and pressing the shutter button.
Clear skies and dark nights
Preparation is key and there are several important factors to fulfil before you even consider reaching for the camera. First and foremost, you need clear skies and a dark night, so refer to the weather forecast to find out if the coming evenings will be cloud-free. A night sky free of cloud provides a clear view of the heavens. Even better is if the night is still – gusts of wind can create problems by causing vibrations and movement to camera and tripod which will blur the image of a long exposure.
Of greater importance is a dark night, less so if photographing something as large as a full moon, but especially when trying to see constellations of stars or distant galaxies. Strange as it may sound, some night skies are darker than others. This is because a dark sky is largely determined by two things: the phases of the moon and your location. After sunset, the moon is the greatest light source in the night sky, but during the phase of a new moon no light is reflected and the moon cannot be seen, making the night sky even darker.
Light pollution from built-up towns and cities also blocks out much of the starlight to be seen from Earth, so the ideal location for seeing stars is far away from urban areas, in low lying country, or better still, remote deserts, mountains, or out to sea. This is why the world’s great astronomical telescopes are found on high mountain tops, islands, or flat uninhabited terrain. Some parts of the UK, such as Galloway and Dumfriesshire in Scotland and the Isle of Sark in the Channel Islands, have been designated dark sky preserves by the International Dark Sky Association.
So, for your night of stargazing, pay attention to the weather forecast and know of a location away from the lights of a built-up area that will guarantee a good view of a large expanse of sky. If your main interest is a full moon, then obviously you need to know which night the phase will be brightest. Also, look up the time of the moonrise and hope that the weather forecast is for a night free of cloud. Of course, at some times of year moonrise occurs during daylight hours, so you need to plan ahead and pinpoint those dates and times during the year when the moonrise is at night, then hope the clouds stay away on your designated evening!
A full moon looks biggest when it rises close to the horizon. You can make it look even bigger by using a telephoto lens and including within the frame a silhouetted landscape or buildings on the horizon, with the moon just above. This way, any full moon can look like a supermoon! Of course, you should always fix the lens and camera to a tripod. A telephoto zoom, covering a focal range between 200mm and 400mm or longer, is ideal for this purpose. Ensure any image stabilisation systems are turned off and also switch off the autofocus and use manual instead. When it comes to shooting the moon and the stars, the subject to camera distance is infinity, so simply turn the focus ring to the infinity setting and lock it there.
The moon and Earth are constantly moving, but the desired result is a sharp, unblurred image of the moon, so use a fast shutter speed, say 1/500sec, and a mid-range aperture between f/5.6 and f/11. Meter directly off the light of the moon, increasing the ISO setting to a level that ensures a fast enough exposure.
Milky Way inspiration
Photographing the stars requires a different approach. The improved light gathering ability and image resolution at higher ISO settings in modern DSLR cameras has led to many photographers making wide-angle compositions of the Earth’s home galaxy, the Milky Way. By choosing a dark night (usually during the new moon phase), and a location free of light pollution, the light of this galaxy and other constellations are vividly recorded on the image sensor.
However, such images require long exposure times – the longer the shutter is kept open the more light points and details are recorded, including fast moving stellar features such as shooting stars. When making such long exposures (also known as time exposures), it is vital that the camera and lens remain absolutely still, fixed firmly on a tripod. When using an ultra wide lens, or even a fisheye, some photographers even place the camera on the ground with the lens pointing straight up to the sky. This can work but it becomes more difficult to ensure that no-one, photographer included, enters the periphery of the frame during the exposure!
The longest time exposures are often made when photographing star trails. These record the stars as circular lines across the sky. With some exposures lasting several hours, the effect is to show a night sky of partial concentric circle of light around a central point in the frame – the Polar star.
As well as making amazing photo subjects, let’s not forget that Blood Moons, full moons, star trails and the Milky Way can also make spectacular backgrounds. This is a trend being adopted my many landscape photographers, thanks to the vastly improved image resolution obtainable at very high ISO settings of 6400, 12,800 or more. Prominent landmarks such as desert arches and mesas, canyons and gorges, that people flock to photograph by day, are being visited again at night for a long exposure that records the same geographical site, but against a background sky filled by the brilliant stars of the Milky Way. Even wildlife photographers are using the same technique, but with the addition of flash fired remotely (or with an infrared trigger), when the intended subject, a nocturnal species, wanders into frame. The shutter continues to remain open to record the ambient light of the background stars and galaxies. This is a new and exciting style of photography that has transformed an established technique (time exposures) thanks to the high ISO performance made achievable by modern camera technology.
Choose a location away from the lights of a built-up, urban area. Listen to the weather forecast and look out for a clear, still and cloud-free night.
Fix the camera securely to a tripod and ensure the standing surface is as stable as possible. If your lens or camera has an image stabilisation control, switch it off.
Experiment with shutter speeds. Vary the amount of time you keep the shutter open and check the results on the camera monitor.
Use autofocus. The camera to subject distance is infinity after all, so switch off AF, and turn the focus setting to infinity.
Press the shutter button with your finger – instead, use a dedicated remote release or the camera self-timer and the Bulb setting to fire the shutter.
Walk into the frame. You won’t be holding the camera if making a long time exposure with a wide-angle lens, so check the field of view and remember the point in your shooting position that marks the edge of the frame.
Night Sky: A Field Guide for Shooting after Dark, by Jennifer Wu and James Martin, Mountaineers Books, £14.99, softback
Astrophotography, by Thierry Legault, Rocky Nook, £22.99, softback
Night Photography: Finding your way in the dark, by Lance Keirnig, £21.99, Focal Press, softback
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