Astrophotography

Equipment Needed

Camera (with good performance at high ISO)
Wide aperture wide angle lens (around 15-18mm, f/2.8 or wider)
Tripod
Remote Shutter Release

Introduction

Astrophotography is a photographic genre in its own right, with specialized equipment and an incredible array of different methods, ranging from trackers that are calibrated to follow the galaxy through the night to ultra-sensitive technical cameras which are able to see more than our eyes when photographing the stars above.


But oftentimes, the “wow” pictures come from the simple placement of an interesting foreground against the night sky. Using the same principles as with other long exposure photography, it’s easy to work out the settings we need to achieve the right look.

01

SETTING UP THE SHOT

First thing’s first, let’s look back to our exposure triangle and work out what we need to do with the camera settings:


Our aperture, given it’s so dark, generally needs to be as wide as we can get (ideally f/2.8 or wider). And our shutter speed will be limited due to the fact that the earth’s rotation means the stars appear to move across the sky – leave the shutter open too long and you’ll see “trails” where the star have become a line instead of a dot. To keep the stars sharp, we want a shutter speed as short as possible, but certainly no longer than 20 seconds.


This leaves our final variable: ISO. So, with those two aspects fixed, we’re basically using whatever ISO we can “get away with” – one that’s not too noisy, but also not too dark – so we have enough of the stars that we do want, and very little of the noise that we don’t. Ideally, we’re going to be working around ISO1250-1600, depending on your camera’s sensor.


Then, it’s all down to the framing. If you’re able to include the “galactic centre” – that big band of tightly packed stars that appears during certain months – that can immediately increase the level of interest in the shot, but you also need a foreground, so concentrate on finding an interesting subject and then placing the “GC” around it.


If you’re shooting into the moon, you’re going to find the stars are blown out in the shot, so you’ll notice a lot of photographers aiming to shoot during a new moon or small crescent, allowing them control over the light that appears in the shot.

02

CAPTURING AND IMPROVING THE SHOT

Just like with sunset shooting, astrophotography requires a huge amount of patience – “perfect” conditions rarely exist, so it’s all a game of balancing variables and hoping for the best at the exact time you want to shoot. It may take several attempts, over many nights, to get the shot you want, so be ready for that!


One advantage of shooting during little or no moonlight is the ability to “light paint” the subject (even an iPhone torch can be enough in the dark). To do this, start your long exposure and then experiment with bathing the subject in that torchlight for a few seconds. For a brighter subject, use more light for longer – if it’s too strong compared to the stars behind, just dial it back a little.


Remember, however, at all times – you’re exposing for the stars, you cannot change their brightness!

03
POST-PROCESSING

Generally speaking, auto-white-balance on cameras will produce astro images which are a little too warm.


By shooting in RAW, we can cool them down a little (to around 3200K or below) for an accurate representation of the night sky.


Use the noise reduction in your processing software to reduce any remaining, unwanted, artefacts – but be careful, sometimes the software can see smaller stars as noise and try to delete them!

An introduction to astrophotography

Watch the video to get introduced to some of the differences between astrophotography and other long exposure, as well as basic settings that can help you get started.

Astrophotography as a discipline

Astrophotography is, in itself, a discipline within photography. If astrophotography is interesting to you, we recommend that you seek the advice and tuition of those within the field. Although it is long exposure photography, astrophotography uses a different set of equipment and skill set than we cover in this guide. Of course, that doesn't mean you can't achieve a night sky image to be proud of with the camera and equipment you have - and that is why we provided this short introduction to the discipline.

Frame Averaging