Expert insight Shooting for sky and land
Ollie recommends shooting two separate exposures and merging them in software, because for the stars you need to capture as much light as possible in a relatively short space of time – even at the expense of image noise – while for the foreground you can afford a much longer exposure and thus cleaner image, but you’ll need to shoot ‘throwaway’ frames too…
Shoo t the sky frame
It’s vital that the stars are absolutely pin-sharp for nightscapes, and for this you’ll need to set your lens to infinity –
‘∞’ marked as on the focus ring. For precise focusing, set manual focus and engage Live View, then zoom into a bright star, and twist the focus ring until it’s at its sharpest, then recompose the shot. Set the widest aperture on the lens and ISO in the range of 3200-6400, and a shutter speed determined by the ‘500 rule’. This should capture crisp stars, but the foreground will be very noisy.
‘throwawa y’ frames
Ollie shoots a separate exposure for the land at a much lower ISO and lengthier shutter speed of several minutes long – but how long? To quickly judge the exposure length, first ramp up the ISO as high as it will go – such as ISO25,600, and take an exposure of around 10 seconds. The resultant image will look horrible, with extreme noise, but all you’re worried about at this stage is getting decent exposure for the land, so tweak the shutter speed until you’re finally happy with the brightness of the foreground.
Shoo t the land frame
Then decrease the ISO to around 400-640 and double the shutter speed for every stop of ISO you go down. For example, if you got a reasonable exposure at 10 secs at ISO25,600, then reducing this to ISO400 is a six-stop difference, so doubling 10 secs six times works out at 640 seconds, or around a 10-minute exposure. In the resultant image the stars will have turned into streaks, but the land will be much more appealing with much cleaner, richer detail, and seas will smooth into a gorgeous mirror-like surface.