A large maximum aperture is needed – these are referred to as ‘fast' lenses, so look with options that have the smallest f-stop number possible – we'd recommend f/2.8 or faster.
Wide-angle focal lengths allow you to capture a good portion of the night sky as well as some of the landscape for foreground interest. A large maximum aperture is needed – these are referred to as ‘fast' lenses, so look with options that have the smallest f-stop number possible – we'd recommend f/2.8 or faster. If you're looking for a prime lens (a lens that doesn't have a zoom range), you'll have options of f/1.8 or wider, which cost more but tend to produce sharper results.