Having posted a few of my star trails on my facebook page in the past, I have received a number of queries about what equipment and settings are needed to take star trail shots.

It’s surprisingly easy to take star trail or other night images. You do need photographic equipment capable of long exposure and quite a lot of patience. Aside from that, it’s all maths really. The longer the exposure – the longer the star trail.

So, what gear do you need?

So, what gear do you need? Firstly a camera with Bulb function. This will be marked “B” on most cameras but check your manual if you are not sure. Bulb allows you to set any length of exposure. Most standard functions only allow up to around 45 seconds where as bulb allows you to open the shutter for minutes, or even hours, if desired. To prevent camera shake you’ll also need a remote shutter release (cable or wireless) and a tripod. That is all the gear you’ll need, though I also recommend something to sit on and a flask of something warm or alcoholic. 

How do you focus at night?

How do you focus at night? Well, this is a tricky one. Many will just tell you to set focus to infinity, but that’s not precise enough for me. Sure, it will give you an ok effect but it wont be perfectly crisp. If you have the time, I strongly urge you to get to the location in daylight, sort the focus at that point and mark down the settings for later – if you can’t do this, something just short of infinity is a good starting point.

Of course, this is all about having a decent silhouette to focus on – The stars may be, well, the stars of the shot – but you still need a landscape to give definition. Cliffs, trees, houses, anything can work, but you need something as a distinctive foreground. If you do want to shoot just the stars, infinity will definitely work – I understand they are quite a long way away.

What settings should you use?

About 10 minutes will give you the start of an obvious star trail. If you want more, go longer! I have taken shots lasting 45 minutes and even 1 hour. I set the ISO to 100 (yes 100!).

Normally, in low light conditions, we are used to setting a high ISO but we don’t have to worry about the usual issues of camera shake or motion blur so using ISO 100 gives you much better quality. I set the aperture to a relatively shallow depth of field (somewhere around F5.6-F9.0) as this lets more light in and gives a better contrast between sky and landscape.

With all these settings, do experiment! So long as you are warm and safe, you can spend several hours taking multiple shots, changing your settings each time and finding out what you like. Consider adding some foreground light – just briefly lighting up a feature with torches or turning lights on in a tent, or house, can have amazing effects. Be careful to balance the lighting though – a few second of torch light will still show up on a 10 minute exposure!

You are better off shooting when the moon is new

You are better off shooting when the moon is new to make the stars stand out and get real silhouettes, but many of the shots I have taken are during full moon, causing the landscapes to look bright, almost day lit. Of course, the UK is blighted by light pollution, but don’t let that put you off – The pollution can cause some amazing effects in itself – check out the red sky over Monument national park. 

Finally, If you want to get a real circular appearance to your star trails, don’t forget to include the Pole star in the shot. This is the one star that wont move, while all other stars will rotate around it. Above all else, have fun and hopefully get some great shots.