Astrophotography is incredibly fun, and capturing subjects like the Milky Way is easier than you think.
Have you ever wanted to capture stunning pictures of the night sky but weren’t really sure what you need to do? If so, this beginner’s guide to astrophotography is for you. This quick guide will look at astrophotography basics and cover things such as camera settings and the 500 rule. We’ll also take a quick look at how to plan your shoot and how to stack images. So, if you’re ready to try your hand at astrophotography, head on past the break.
Astrophotography scares a lot of photographers. Many people think capturing images of the Milky Way is hard. However, it’s actually pretty easy if you remember a few key settings. Most cameras these days are more than adequate at high ISO levels. This means you don’t even have to use ultra-fast, expensive lenses (although it will obviously help). You can see three of our favorite lenses for Astrophotography here. You can also check out three of our favorite cameras for Astrophotography in this roundup. If you want to try capturing the Milky Way this astrophotography season, follow the quick guide below. You’ll be amazed at what you can capture.
Camera Settings and the 500 Rule
There are just a few things to remember when it comes to settings for Astrophotography. For some of us, these will be obvious, so this section is a warm welcome to the newcomers. Become familiar with your camera; the best way to shoot is in manual mode. If you’re new to manual mode, don’t worry. It’s really not as complicated as it may seem. Also, make sure you are shooting RAW. You will need to work on your files during post, and you’re going to want as much data to push and pull as possible.
Astrophotography ISO Settings and White Balance Settings
Selecting a higher ISO will introduce noise into your image, but there are ways to remove it later. You need to use a high ISO so that your camera can pick up as many stars in the night sky as possible. Remember, those dots of light are tiny, and your camera has to be able to see them. A good starting point is ISO 2000. Take a test shot and see how it looks. Usually, I end up between ISO 3200 and ISO 6400 in really dark areas and around 1600 to 2000 if there is ambient light. Use these numbers as a base and play around. There is not one ISO setting that fits all. When it comes to ISO, you can manually set it to around 4000k. If you are shooting RAW (which you should be), you can also alter it to your taste when editing.
Astrophotography Aperture Settings
Aperture settings for astrophotography are as easy as pie. Just set your lens as wide open as it will go. Have an f1.8 lens? Set it at f1.8. If your lens can only go to f2.8, set it to f2.8. If your lens is slower than this, no worries. Set it wide open and just increase your ISO or shutter time. Let all of that glorious starlight in! This is one setting that just needs to be set and forgotten about.
The 500 Rule and Avoiding Star Trails
The 500 rule dictates how long your shutter speed can be in relation to the focal length of your lens. Divide 500 by the focal length, and you’ll get your maximum shutter speed. This number is the longest amount of time you can shoot before you start to get star trails. For example, if you have a 14mm lens, your max shutter speed would be 35.7 seconds (500/14). Here are a few examples of common focal lengths used in astrophotography:
- 12mm: 500/12 = 41.6 secs
- 14mm: 500/14 = 35.7 secs
- 18mm: 500/18 = 27.7 secs
- 24mm: 500/24 = 20.8 secs
If you’re shooting with a crop sensor camera, you’ll need to multiply your focal length by x1.5 (x1.6 for Canon) and divide by 500. For example, if you shoot with a 14mm lens on a Canon APS-C camera, your focal length would be 14 x 1.6. This equals 22.4mm. You then just divide 500 by 22.4, and you’ll get your max shutter speed. It would be 22.32 seconds. Just remember that you don’t always have to use the maximum exposure length. Your actual shutter speed may be quite a bit less: it just depends on how much ambient light you have around you.
Getting the Shot
This is where the fun begins! Your camera is set, and you’re ready to push the shutter button, but wait! Where’s the Milky Way? When’s the best time to go and shoot? Don’t worry. There are lots of tools that will make getting the shot super easy.
What does a typical astrophotography image look like? Ideally, you’ll want to include objects in the foreground so that your shot can have some interest. By including foreground objects, you can give a grand sense of scale. You can spice things up a bit by trying your hand at light painting too. Shining a light on your foreground objects during the long exposure can add some incredible depth to your image. Placing yourself in the image is always fun too. There is, of course, nothing wrong with just capturing the magnificence of the Milky Way by itself. Still, any time you can include other items, you should. Play around and have fun. The extra effort will pay off in a big way.
Ideal Astrophotography Conditions
Absolutely perfect condition will be rare to get. Still, with a little patience and planning, you can time things to where conditions are pretty close to it. The first thing you need to keep in mind is the phase of the moon. Any hint of the moon in the sky will drastically reduce your chances of getting good Milky Way shots. The moon is simply too bright, and it will wash out the stars in the sky. So, plan accordingly and know your moon phases. No moon is absolutely the best.
You need the winds to be low too. Ideally, the wind will be blowing no harder than 5-6 mph. You’re going to be using a tripod for long exposures, and any movement caused by the wind will ruin your shots. You also need the sky to be cloud-free so that you have unrestricted views of the galactic center. Clouds in the sky will also reflect ambient lighting from surrounding cities, introducing a horrible orange glow into your images. You can use light pollution filters like this one from IRIX to help cut it out. Use this Dark Site Finder to see how far you will need to travel to get away from city lights.
Locating the Milky Way With Apps
Smartphones make locating the Milky Way easier than ever. You can use apps like Stellarium and PhotoPills to see exactly where the Milky way is at any time. Simply load the app, hold your phone up to the sky, and the Milky way will be displayed on the screen. Hold the phone above your camera and rotate your tripod’s head until your camera points in the right direction. And then all that’s left to do is release the shutter.
Take Multiple Images
Shooting at high ISOs can create a lot of noise. You can reduce the noise problem by taking multiple images and them stacking them in post. The more shots you take, the more natural noise reduction will occur. If you’re going to do this, take a minimum of ten images. Be careful not to move the camera in between shots, though. This will make things harder. The stars are constantly moving through the night sky as the earth tumbles through space. So, over 5 minutes of getting 15-second exposures, the stars in your images will, of course, be in different locations. Some amazing pieces of software can help with this, though.
Seqautor is a free star stacking program for Windows-based PCs. Sequator will take into account your location, the rotation of the earth, and the position of the stars. The software will then realign all of the stars for you so you end up with razor-sharp images. Because you have multiple files, the software will average out the noise in your images and leave you with beautiful, noise-free photos. You can even go further by taking dark images. You simply put the lens cap on your camera and take the same amount of dark images as your Astro scene. The software will then map the natural noise from your sensor and will remove that as well. All you’ll have to do then is edit the image to your liking.
Astrophotography Is Incredibly Rewarding
Astrophotography may seem hard at first, but there really isn’t a lot to it, as you can see. Compose your image. Set your aperture as wide open as possible. Find your max shutter speed using the 500 rule, and adjust your ISO. It’s that easy.
Great astrophotography is all in the planning. It’s about finding a great location, and it’s about knowing the right time to go and shoot. Keep in mind the weather conditions and phases of the moon. Having the right gear like wide, fast aperture lenses will surely help. Having a sturdy tripod and light pollution filters will do a world of good too. However, putting effort into getting away from city lights and committing to being an early riser or a night owl will pay off in a big way. Get out there and see the beauty of the night sky. I guarantee you’ll be hooked instantly. Astrophotography is an emotionally stimulating genre of photography that everyone needs to experience.