So my editor has charged me with sharing some of the photographic knowledge I keep stored up in my head. He has also charged me with being concise, the idea being that you rock up to the post, digest it in a matter of minutes and head off into the world ready to apply what you’ve learned.
Let’s see if I can manage that. History would suggest not, but I’m game to try!
The two types of star shot
There are two types of star shot available to you, unless you happen to work for NASA.
One is a fixed shot of the stars, highlighting an awesome bit of sky such as the Milky Way, like this:
The other is the classic “star trails” shot, where you take advantage of the movement of the earth through the heavens, and create funky lines, like the one at the beginning of the post.
Now I’m going to tell you how to do both of those.
Gear you need
You are going to need a camera, and also a tripod – or at the very least, something upon which the camera can rest entirely still for 20-30 seconds.
If you are shooting star trails, you’ll need a remote release, spare batteries, a flask of coffee, and, depending on your location, warm things to wear.
A flashlight is also likely to be handy so you can see what you are doing. To conserve your night vision, put a red filter over the light.
Finally, if you have a smartphone, a free star application can help you find the parts of the sky you are interested in.
Whatever type of star shot you want, you need to be in Manual mode, with your aperture as wide open as it can go. I’d also recommend shooting in RAW as it will make post processing a lot easier.
It’s unlikely your camera will be able to focus in the dark, so manual focus on infinity (or near to it). If you have a camera that lets you focus using the back display, use that to get the focus pin sharp.
Then, you control the amount of light by setting the ISO rating and the shutter speed, at which point you need to decide the type of shot you are taking.
Fixed star shot
If you want to take a fixed image of the stars with no movement, then you need to figure out how long you can expose the image before the stars start to track across the sky.
This is very easily done (I promise!) with the “rule of 600”.
Put simply, divide the number 600 by the focal length of your lens (a number in mm), to give you the maximum number of seconds the shutter can be open for.
For example, if shooting with a 17mm wide angle, I would divide 600 by 17, giving me a maximum exposure of around 35 seconds. The two “fixed” shots in this post were shot with exposures of 30 seconds at a focal length of 17mm.
Depending on the speed (maximum aperture) of your lens, you now need to pick an ISO rating that gets you the shots you want.
Not all cameras are created equally, and it is here that more expensive cameras with bigger sensors can really shine through, picking up wonderful amounts of light with low noise even at higher ISO ratings.
Experiment with a few shots at different ISO ratings. Use the maximum exposure time available to you without the stars starting to blur, keeping the ISO to acceptable noise levels, until you get something you are happy with.
Lastly, don’t forget the composition! Great star shots often have something in the foreground, either illuminated with a torch or an interesting silhouette. Again, experiment with your surroundings to see what works.
- Camera set to manual, shooting in RAW
- Long exposure noise reduction enabled, if available
- Manual focus
- Aperture wide open
- Use rule of 600 to choose shutter speed
- Experiment with shutter speed and ISO settings to get the best quality shot
- Find interesting foreground objects to make the shot more exciting
Moving star shot
Capturing star trails is a more accessible form of astrophotography, as the longer exposures mean you can use lower ISO settings and thus get around noise limitations.
You will need a remote release trigger for this kind of shot, as holding the shutter button down isn’t practical.
The big question is – how long to expose for? A mistake that is often made is just to leave the camera shooting for the whole length of the exposure, resulting in one image.
This isn’t a good idea for a couple of reasons. One, over a prolonged exposure, random noise flecks appear in the image. Two, if your battery dies, you lose that shot and the night is wasted.
You won’t want to use long exposure noise reduction in this case as it will leave gaps between the trails.
You should also decide on the sort of movement you want. The stars rotate around the poles, with the North Star in the northern hemisphere providing a handy reference point. This star doesn’t move, and all the other stars will rotate around it.
Also note that the further from that “pole star” the other stars are, the more they will track.
- Camera set to manual, shooting in RAW, BULB mode
- Long exposure noise reduction disabled
- Manual focus
- Aperture wide open
- Compose the shot based on the star position and foreground objects.
And that is it for a quick introduction to astrophotography! Got any questions? Fire away in the comments below. Otherwise – happy shooting!