TO INFINITY AND BEYOND

Turn your gaze heavenwards with these wide-angle primes, ideal for capturing the night sky

Ultra-wide-angle prime lenses are enormously versatile. They’re great for everything from shoehorning architectural interiors into the frame when your back’s against the wall, to shooting cityscapes and sweeping landscape vistas. Venture out on a star-studded night, meanwhile, and you can take in the majestic panoply of the heavens above. On a full-frame camera, a focal length of around 14-20mm is ideal.

You’ll need a lens with real pulling power when it comes sucking in light, so it pays to go for a fast aperture of around f/1.8 to f/2. This avoids sending your camera’s ISO setting into the stratosphere, as you keep exposures short enough to stop stars and other celestial bodies in their tracks, so they don’t appear to be trailing across the sky.

It’s not just the speed of the lens that’s important: for effective astrophotography you’ll want good sharpness across the whole image frame. Unwanted aberrations that occur when using a fast lens at its widest aperture can be a spoiler. These include vignetting, ‘coma’, which gives pinpoints of light a comet-like tail, and ‘astigmatism’, which creates lines from dots of light. Some lenses are prone to a combination of coma and astigmatism, often referred to as ‘batwing coma’. Another potential problem is spherical aberration, which can cause points of light to take on a halo effect.