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Whether you call it star photography or astrophotography, capturing the beauty of the stars is something you definitely should not miss on your next trip into nature.
How I did it:
For star photography, you need a lot of light. I chose f/4.0, since this is the widest aperture possible with the Sigma 10-20mm zoomed out all the way at 10mm. Obviously, for this shot you want everything to be as much in focus as possible. Using a wide aperture while focused on infinity doesn’t reduce your depth of field if, like in my photo, there are no elements close to the camera. The trick to solving the problem of having a close foreground element and still wanting everything in focus is, to take two photos at the same aperture, one focusing on the stars – so infinity – and another focused on that element and then combining them in photoshop.
Switch to manual focus, since your camera would have no idea what to focus on in complete darkness. Without an element directly in the foreground, focus to infinity (usually the little sideways 8 on your lens) and everything should be nice and sharp. Otherwise, take two photos and do some photoshopping later on.
To figure out how long you can maximally expose, use the 500 Rule: Divide 500 by the focal length of your lens and the resulting number gives an idea, how high you can go in seconds. (Some sources say 600, others say 450 – either way, 500 seems to be a good medium.) Any longer and, due to the movement of the earth, the stars will start to create trails. You might want to go a bit lower than that, just to be safe. I chose 30 because that’s as high as the timer goes and I didn’t want any trails to appear on the edges of the image due to the distortion from the super-wide lens. While 30 seconds is a good number to orient yourself on, it doesn’t always apply. The longer your lens is, the shorter your exposure will be. Lets say you shoot at 20mm, you could only expose for 25 seconds, and that would already be pushing it.
Wadi Rum is a desert with basically no light pollution around at all. As a result, the stars show magnificently in the sky. Since the stars didn’t need much extra help from me in the ISO department, I set the ISO very low at 200 and with the combination of the wide aperture, this made them pop nicely without adding any extra noise. Additionally, the rock formation and tents were lit up perfectly by the Bedouins, not too bright or too weak, and keeping the ISO low prevented those elements from being overexposed. If you’re shooting near a town or somewhere the stars aren’t shining so brightly, you will probably have to up your ISO to at least 1000. Compare my photo from Wadi Rum with one of the shots from Petra at Night, where the nearby town of Wadi Musa, as well as a rising moon, had me crank up the ISO all the way to 1600.
It doesn’t matter if you are a brain-surgeon with the most stable hands on the planet – keeping the camera rock solid during a long exposure is a must. You could set the camera on the ground or some other stable surface, but usually this is only semi-ideal and will mess up the composition of your photo anyway. Do yourself the favour and bring a tripod. Set the camera to a 2 second timer to prevent any disturbances or, even better, buy a remote shutter release.
Although the milky way was right behind me in the Wadi Rum picture, the combination of the amazing rock formation and lights on the tents were just too good to pass up. I chose a little fewer stars in favour of a nicer composition. Finding a good location and the key elements to your photo is a must. Just stars and an empty field are boring to look at and might result in an OK image, but won’t produce anything outstanding. Find something that pops out in the foreground. That can be a building, a mountain, a tree, a road – anything really, that draws the eye and makes the composition more interesting. Additionally, watch out for light pollution. Make sure to avoid any bigger cities, but even small towns can produce enough light to mess up your photo. So get out and into nature!