A major meteor shower, such as the Perseids in August or the Geminids in December, is a treat for anyone with a bit of patience to sit out and watch. But if you have a reasonably good camera with the ability to take time exposures, you could try to photograph some too as a lasting record. Here is how to photograph a meteor shower.
This really rules out using cheaper snapshot cameras, or those built into today’s smartphones. Meteors appear randomly and in any direction, and they are too sudden and swift for you to be able to spot one and then take its photo.
Instead, you need to aim the camera and open its shutter for a while in the hope that you’re lucky and a bright meteor appears right where you are pointing. So your camera must have a manual setting where you can open the shutter for at least several seconds. You must also be able to focus the lens manually, as starlight is usually too faint for the autofocus to work, and your camera will spend all its time searching for focus and running down the battery. There is usually a switch on the lens of a DSLR camera to select manual focus.
In the days of film, where every precious frame counted, amateur astronomers got used to seeing bright meteors appear just after they had ended an exposure, or just outside the patch of sky being photographed. Today’s digital cameras mean that amateur astronomers can rattle off hundreds of shots in succession without worrying about the cost. The chips that replaced film are much more sensitive too, meaning that fainter meteors may be imaged than before.
I have had a fair amount of success photographing meteors with a Canon digital camera, in my case the consumer model the EOS 600D. It is ideal because you can set it to take continuous exposures, providing you have a cable release, so that you don’t have to keep pressing the shutter yourself. This way, you don’t even need to stay with the camera. I used mine to photograph the Quadrantid meteor shower on a chilly night in early January this year and was able to go back to bed for an hour or two at a time, popping back to change the battery and check all was OK. (The camera was pointing out over the sea from a sheltered balcony, so I did not need to worry about the possibility of rain!)
The first important rule in taking time exposures of the sky is that you need to hold the camera steady. A photographic tripod, or similar, is therefore essential, and you should have a threaded hole in the base of your camera into which the head of this – often a detachable plate – can screw. This should be set up in a dark location, away from any street lights or other light pollution, so it is best to practise mounting and operating the camera beforehand when you can see what you are doing more easily.
Next, you need to set the speed of the camera – the ISO – in the camera’s manual settings. With a clear dark sky, you should set this to at least 800. Excellent conditions and an absence of interfering moonlight might allow you to go to 1600 or even higher. Experiment and see what you get when you review the first test shots.
You will next need to ensure the camera lens is in focus. Modern cameras have “live view” settings to make this easier because you cannot always rely on turning the lens, in its manual mode, to the little squiggle that marks “infinity”. Instead, select live view, then zoom in until you can see a bright star, and turn the lens until that star becomes a sharp point of light. Make sure the lens is fully open when you focus – turn the part of the lens barrel that controls the iris of the lens so that it is set to its highest f number. To catch more meteors, you will want to have the lens wide open (at a high f number) in any case, though “stopping down” by a stop can improve the picture if the lens is not of high quality.
It is important here to use a solidly built lens if you can. I found, to my cost, that the light zoom lenses sold as standard with consumer DSLRs are OK for daytime shots in autofocus, but are so flimsy that they easily slip out of focus in manual mode. (I took my Canon to Iceland a couple of years ago to photograph the aurora, travelling light with just cabin baggage, and so relied on my kit lens. It was only after a fine auroral display that I saw that my stars were no longer pin-sharp.)
I now have a much more robust 10-20mm Sigma lens on my Canon with a focus that stays just where you turn it. It is a lovely wide-angle lens that covers a large area of sky, increasing the chances of catching a meteor, and I am very happy with it. Even so, it is wise to check regularly that it is still in focus (and, on humid nights, that the lens is not misting over with condensation). The downside of the lens is that it only goes up to an f number of 3.5. As an alternative, and I must take more comparison shots, I have an excellent Samyang 12mm prime lens on my Fuji X-M1 camera – it is a robust design with good quality optics, and is also sold in the USA under the Rokinon brand.
One benefit of the Canon EOS range is that you can employ lenses from various old SLR film cameras by adding an inexpensive adapter. I have several Olympus Zuiko lenses made for their OM cameras. These were beautifully made pieces of glass and the wide-angle lenses would be useful for meteor work if you already have them.
Finally, it helps to have that cable release if you want to take shots continuously. My Canon release, pictured, is inexpensive. I simply set my camera’s drive mode to continuous, using the leftmost of the central ring of four buttons on the back of the camera, then push and slide forward the release button to lock it. Pressing and sliding back the release button ends the run of exposures.
Even an exposure of 20 seconds, using a wide-angle lens, will reveal that the Earth is turning by recording the stars as short trails. If you want them to look more like points of light, then could mount your camera on an equatorial telescope mount with a motor drive, or one of the dedicated driven camera mounts such as the AstroTrac. Otherwise, keep the exposures to just 10 or 15 seconds long.
When I tried this set-up for the January Quadrantids, I was surprised how many meteors I had captured. The fact I left the set-up to work unattended meant that I had to scan through hundreds of images on my computer to spot the meteors, ignoring any aircraft trails or satellites that had been photographed. I was still finding some of the fainter meteors a few days later!