A Comprehensive Guide to Photograph the Milky Way

For many photographers, including myself, there are few things more rewarding than capturing spectacular images of the night sky. In particular, photographing the milky way from here on Earth is one of the most satisfying things you can do with your camera.

What many people don't know is that shots like that are one of the purest forms of wide-angle astrophotography and that they really don't require a lot of sophisticated equipment. What you do need is the right basic gear and a little bit of basic knowledge. I'm going to provide that last item in this article, including a few tips that should help you successfully photograph the Milky Way in a short amount of time.

Basic Equipment

Let's start with a list of the photography gear you'll need:

• An SLR Camera with manual exposure mode: You can follow these same procedures with a film camera, but to keep things simple, I'll be describing the process with a DSLR. A full-frame sensor is ideal, but crop sensor cameras will do a good job with a lens that matches them well. You're not going to want to let your camera's metering system do the work in this instance, so look for that M setting on the exposure dial.
• A fast, medium to wide-angle lens with manual focus capability: You can photograph portions of the sky with a "normal" 35mm or 50mm lens. For the most part, if you're trying to capture the Milky Way, a wide angle lens with a focal length of 24mm or shorter will yield more dramatic results. I really like the Irix 15mm f/2.4 Blackstone, the Irix 21mm f/1.4 Dragonfly and even the Irix 30mm f/1.4 for these shots. Because stars aren't a good target for an autofocus system, so you'll be focusing manually. That, too, makes the Irix wide angle lenses with manual focus an excellent choice.
• A sturdy tripod: Yes, there are other ways to mount your camera for long exposures, but I believe a tripod works best for astrophotography. Remember, even the slightest movement will cause blurring at these distances. Be prepared with a sandbag or other weight for lighter tripods or breezy conditions. Be sure your tripod head locks firmly and allows you to point your camera upward.
• A remote shutter release: Many DSLR cameras will let you set the shutter speed for up to 30 seconds or more, and most of them include a delay timer for the shutter of 2 or ten seconds. Personally, I prefer to keep my hands off of the camera as much as possible for star shots. An electronic or IR remote is best, and an intervalometer will let you take time-lapse sequences, too.
• Other night gear: Keep in mind that you're going to be shooting in the dark, hopefully in a remote location and it may be cold. (In fact, the stars are often clearer on cold nights.) Bring along a flashlight and/or headlight to see your way around and adjust your camera controls. Proper clothing and something warm to drink are probably a good idea. Nocturnal animals can be a problem. Use your common sense and be prepared.

... a Milky Way shoot takes a little extra planning.

Preparations for Photographing the Milky Way

Aside from getting your equipment together, charging your main and spare batteries and all those things you already know you need to do, a Milky Way shoot takes a little extra planning. There are several factors that can affect the outcome, so it's important to check each one.

• Light pollution: For the best results, getting away from city lights is essential. The darker the surroundings, the easier you'll find the area of the sky you want to photograph. Just like you, your camera will "see" the Milky Way better when it's really dark. Use a light pollution map like this one to find a good location near you.
• The moon: The moon is always a factor in star photography. The brighter it is, the fewer stars you'll see. If it's in the frame of your shot, it will be overexposed and hide some of the stars that are visible. You can use the PhotoPills app to know when the moon will be at its brightest.
• Weather: Obviously, this is one of the most important factors and one that can't be determined too far ahead of time. Keep a close eye on the weather where you plan to shoot and wait for clear skies and little chance of fog or other conditions that might complicate matters.
• Timing: Depending on where you're shooting, different areas of the Milky Way will be visible at different times of the year. Although part of the cluster will always be visible, some parts are better than others. We suggest the PhotoPills app again to find out where the Milky Way and stars will be at a specific time.

Let's Get Down to Business

Alright, you've prepared, you've brought everything you need and you're out there under the stars, ready to capture all that beauty. It's time to get down to the how-to! Before you start, though, take a couple of minutes to just appreciate the experience. These opportunities to get away from everything and find out what real peace and quiet is like are priceless.

OK, let's do this. Start by setting up your camera and tripod, have your light source handy and your remote where you can reach it easily. Now let's preset everything we can.

Shoot RAW

If your camera will allow you to save your photos as RAW files, use that setting. You'll be glad you did when it's time to process them. Because RAW files contain all the data recorded by the sensor, you'll have much more latitude in your adjustments.

Exposure Settings

Were going to be going full manual with exposure, because your meter simply isn't going to work with light sources as distant as the stars. You should know something about the Exposure Triangle and we'll cover that in depth in a separate post. For now, we'll use some guesswork combined with a little bit of science.

Shutter speed: The most critical part of your exposure is going to be shutter speed. Why? Because the longer your shutter is open, the more light you gather from deep space. There's a limit, however, to how long you can keep the shutter open. Why? Because the rotation of the earth will cause the stars to appear to move in the frame, and as they move across separate pixels in your camera sensor, they'll create light trails. Star trails can be fun to photograph, too, but that's not what we're after here.

The maximum length of time the shutter can be open varies according to the focal length of the lens and the size of the sensor. The formula is somewhat complicated, but there are rules of thumb you can use. For a full-frame sensor, the most common is the 600 rule. Simply divide 600 by the focal length of your lens. For example, with a Canon 5D and my Irix 15mm Blackstone: 600/15 = 40 seconds. With an APS-C crop sensor, say the Canon 60D, use the 400 rule : 400/15 = 26.6 and round down to 26 seconds.

Remember, these are just rules of thumb, and you'll want to take some test shots for each shoot, zooming in on the preview to look for trails. If they are evident, increase your shutter speed (lower the number of seconds) slightly and try again.

Aperture: The correct aperture setting for this project is simple: shoot wide open. You want to gather as much light as possible while the shutter is open. Use the widest setting (lowest f/number) available on your lens. This is another area where the Irix 15mm Blackstone really shines. With a maximum aperture of f/2.4, it's a great choice for star shots.

ISO: Choosing the ISO setting is also fairly straightforward, but you need to know a little bit about the performance of your camera sensor. You'll want to use the highest setting that doesn't produce too much digital noise, and noise tends to build up faster in low-light conditions. For the most part, larger sensors are less prone to this problem and you can push the ISO higher.

I recommend starting at about ISO400 for crop sensors and ISO800 for full-frame, and working your way up from there. You won't really be able to judge the results on this until you're processing the photos, so take several shots at different ISO settings and determine the range that's best for you when you process the images.

Once again, my Irix 15mm lens comes to the rescue, with a solid click-stop on the focusing ring at infinity.

Focusing

Sharp focus is critical for star photography, and can be difficult with many lenses. The most common method is to focus at infinity, then find a bright, distant object and fine-tune the setting by zooming in with Live View. Unfortunately, some lenses lack an infinity mark on the scale, and for most that have them, reading it in low-light conditions can be difficult.

Once again, my Irix 15mm lens comes to the rescue, with a solid click-stop on the focusing ring at infinity. Although the markings on the lens are easier to see at night than most, I don't even need to look at them, because I can feel the detent as I turn the ring. There's plenty of room beyond the mark, if I need to tweak the focus a bit.

Get creative.

Composing Your Shots

I won't go into a lot of detail on composition here, because it's also a subject that covers a lot of territory. (You're welcome.) What I will say is that you can take your Milky Way photos from "nice" to breathtaking by taking the time to learn and apply some good composition techniques.

Include the horizon in some of your shots. Frame some shots to include features of the landscape – the long exposure will surprise you with what shows up. Create silhouettes with natural or artificial subjects. Use your flash or flashlight to "paint" some of the surroundings with light while the shutter is open. Shoot over a lake or bay to reflect the sky and get that nice, dreamy long exposure effect on the water. Get creative.

Processing

Once you get back home with your photos, the fun continues. You'll want to examine your shots at 100% for noise, and use the noise reduction in your software to eliminate as much of the "grain" as possible. This is where you'll find out what ISO ranges work best with your camera and software.

The adjustments you apply to the images will depend on the quality of the original image and your personal preference. Whether you're planning to print the images or display them digitally will also make a difference. Cropping, sharpening, contrast adjustments, levels, and curves are all common processing steps. Your creativity will determine what works for you.

Conclusion

I hope you'll find this guide useful. I've tried to provide all the information you'll need to get off to a successful start in shooting the Milky Way. With this little bit of knowledge, some practice and your own imagination, you should soon be capturing those incredible images you've dreamed of. Have fun!