An Updated, Comprehensive Guide to Photographing the Milky Way (Part 1)

A few years ago, we published an article describing how to shoot the Milky Way. While it was and is a good resource, widefield astrophotography has changed, thanks to improved technology and techniques. With that in mind, we're providing our readers with this new version, updated to include new information and help you make the most of your endeavors.

Opening Image: The Milky Way, ©Stefano Perrone. Captured with the Irix 15mm f/2.4 lens.

If you've ever gazed at those incredible images of our galaxy from Earth and wished you could create your own, you're in luck. Milky Way photos don't required a lot of sophisticated equipment. With just a little bit of know-how, they're well within the reach of most photographers. We're going to provide you with a list of basic equipment and the things you need to know to get started. The rest is up to you and your own creative muse!

Basic Gear for Digital Milky Way Photography

While it's certainly possible to capture the Milky Way on film, the focus of this tutorial will be on using a digital camera. One of the advantages of digital photography is the ease of manipulation of a photo, once it's been taken. That can be a significant factor in making the most of a night of shooting the stars. We'll discuss that in detail later. For now, here's the list of equipment you'll need to capture the view of our galaxy.

• An DSLR or mirrorless camera with manual exposure mode: A full-frame sensor is ideal, but crop sensor cameras will do a good job with a few caveats. In particular, most crop sensors will generate more noise during long exposures and at high ISO settings. You’re not going to want to let your camera’s metering system do the work in this instance so plan to set your exposure manually.
• The Irix 15mm f/2.4 wide-angle lens.

The Irix 15mm f/2.4 lens has become one of the most popular on the market for Milky Way photography. With incredible sharpness, near-zero distortion and a host of features including an innovative focus lock, it's become a favorite of astrophotographers around the world.

• A sturdy tripod: 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 morel Most also include a delay timer for the shutter of 2 or ten seconds. It's best to keep your hands off of the camera as much as possible for star shots.
• An electronic remote is best, and an intervalometer will allow you to take multiple exposures for stacking as well as time-lapse sequences.
• 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 headlamp 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.

Helpful Equipment

While the list covers the basics, there are a few items that can make capturing and processing successful Milky Way photos easier. The list below will help you determine what you may or may not want to invest in.

• An astromodified camera: A standard DSLR or mirrorless camera is suitable for the job, but if you plan to dedicate a great amount of time to Milky Way photos, you may want to consider having your camera modified or purchasing a modified camera.
• Astromodification can involve several options. Filters over the camera sensor may be removed or replaced. This changes the range of light frequencies the sensor is sensitive to and improves overall sharpness. A cooler is often installed for the sensor as well, to reduce the amount of noise generated during long exposures.
• This is one of the more expensive options, so it's not for everyone. We recommend visiting Spencers Camera & Photo , an authorized U.S. Irix dealer, for detailed information on his camera conversions and pre-modified cameras.
• PhotoPills App: Having a lot of information at your fingertips will make shooting the Milky Way much more rewarding. This phone application will help you plan your outings, from when and where to spot the galaxy, to keeping track of the phases of the moon, to calculating exposure times for pinpoint stars and even settings for time lapse photography.
• It features many more functions for other types of photography as well. It's available for Android on Google Play and for MacOS on the Apple store. The cost is $9.99 and it's a great investment!
• Light pollution filter: Even in relatively dark areas, you'll often end up capturing the glow of nearby towns or other lighted areas, especially when there are clouds in the sky. A light pollution filter can help eliminate the yellow glow. Irix offers a filter that fits the front threads of our 15mm lens, as well as other standard thread sizes. You can find it here.

Choosing Where and When to Shoot

There's a lot to be considered when choosing a location to shoot the Milky Way. Obviously, you'll want to find a dark area, as far away from light pollution as possible. You'll also want to check the phase of the moon, since the brighter it is in the sky, the less visible the galaxy will be. Shooting during a new moon, before the moon rises or after it sets is ideal.

It's important to know if, when and where the Milky Way will be visible at the location you wish to shoot. What if you want to capture the galaxy as it rises over a favorite landscape or landmark ?

All of the concerns above are part of the reason we recommended the PhotoPills app. Using its 2D map-centric planner, you can gather all the information needed to ensure the success of your Milky Way shoot. Rather than describe the entire process, we'll simply offer the informative video below, from the developers of the software:

Preparing for your Milky Way Photo Session

Plan to arrive at your shooting location as early as possible. Distance yourself from any other people in the area as much as you can. You never know when someone might decide to use a flashlight in front of your lens or accidentally disturb your setup.

Get your camera(s) set up before the sun sets, using the PhotoPills Planner to judge where and when the Milky Way will make its appearance. You cam also see how it will traverse the sky while its visible. This will help minimize any adjustments you need to make in the dark.

Keep in mind that there may be other photographers in the area. You'll want to avoid spoiling their shots with unwanted lights, too. Rather than using a big flashlight, consider a small UV light. If you're using the Blackstone or Dragonfly models of our lenses, the UV-reactive paint will help you read the markings. The light from a UV source will be less likely to interfere with nearby cameras..

A Word About Image Stacking & Blending

Remember that you're probably going to want to take separate exposures for any foreground included in your images, before you change your settings for the the sky. You can even do this before the sun goes down if you know you've got the right framing for your shots. The foreground can then be blended with the sky in post processing.

You can take multiple images of both the sky and foreground and stack them in post processing to increase sharpness and decrease noise. You're probably going to be taking multiple images of the sky anyway, so stacking is worth considering. For a quick overview of why and how to stack your Milky Way images, See our blog post entitled " Create Sharper Milky Way Photos with Image Stacking and Irix Lenses ". (The article will open in a separate tab.)

If your foreground has a lot of depth, you may want to consider focus stacking, too. This procedure helps create maximum front-to-back sharpness in an image. It's extremely easy to accomplish with Irix lenses, thanks to our unique hyperfocal scale. To find out how, see the article entitled " Focus Bracketing and Stacking Landscape Photos with Irix Lenses ".

Getting Down to Business

After all the planning and prep, you're just about ready to shoot ! Take a few minutes to verify your settings and avoid any disappointments. Here are our basic recommendations:

Shoot RAW

There are a lot of factors involved in shooting the Milky Way. Finding the correct white balance, exposure and focus settings is important and your results won't always be easy to judge on-site. Saving your images as RAW files will retain all the data collected by the sensor. This allows a much wider range of adjustment in post processing. This step can make enough difference to make or break the final images.

Focusing

Proper focus is imperative in a Milky Way photo. If you arrive early enough, you can select a distant object and focus on it in Live View, magnifying the view as needed. After dark, you may use the same procedure to focus on a bright star.

Once you've achieved focus, it's important to make sure you don't disturb the setting. The Irix 15mm lens has a convenient focus locking ring to help you maintain that setting. In addition, the lens features our unique "click stop" at infinity, to help you find that setting, even in the dark.

White Balance

Every photographer and viewer has his or her personal preference for the White Balance setting for the Milky Way. Some prefer to emphasize the blue hues, while others prefer a warmer rendition. Since you're shooting RAW, setting your WB to Daylight will leave you plenty of room to adjust the overall tones later.

In-camera noise reduction

Most digital cameras give you the option to let the camera reduce digital noise in your images. You may often be able to select different levels of reduction as well as simply turn the function on or off.

The software on your camera may actually do a good job of removing noise. The disadvantage is that the process takes time that you'll need to allow for in between shots. It also consumes considerable power, so you'll need to be prepared to change your camera battery sooner.

Even with these considerations, many Milky Way shooters prefer to have the noise reduction on, at a moderate setting. Choose what works best for your equipment and personal preference.

Exposure Settings

Shooting the night sky is one of the most challenging exercises in exposure. Switch your exposure setting to Manual (M) and follow the steps outlined below.

The best Milky Way photos will include elements of the foreground. Exposing both the foreground and sky properly in one shot will most likely be impossible. There are a few ways to compensate for this.

1. You can use the correct exposure settings for the sky, then use a separate light source to illuminate the foreground features, with constant illumination, flash, or painting the foreground with a flashlight or similar device. While can be fun, it can also produce inconsistent results. You'll be setting yourself up for a lot of work if you intend to take multiple photos, which we highly recommend.
2. You can expose for the sky or the foreground and adjust the other area in post processing. This means making considerable adjustments to the other area and you may be disappointed in the results. For example, both high ISO settings and long exposures tend to create more digital noise in an image. This noise can be difficult to remove and will be more pronounced in dark areas that need to be lightened in processing.
3. The method we recommend is first capturing one or more images properly exposed for the foreground. You then continue to shoot with the same framing, exposing for the sky and stars. These images can be stacked and blended in processing.

Shutter Speed

This should be your first concern among the 3 elements of exposure. Why? Because the rotation of the earth will create elongated stars or trails if your shutter speed is too slow. We're going to take a little extra time here, to help you avoid a very common problem with Milky Way photos.

The length of time you can leave the shutter open and still capture pinpoint stars in your images depends on your lens focal length. It also depends on your sensor. For many years, the best method for ensuring sharp stars was " the 500 rule ". You simply divide 500 by the focal length of your lens and use the result for your shutter speed. For instance, when using the Irix 15mm: 500/15 = 33.3333... Rounding that down means you should be able to leave the shutter open for 30 seconds without worrying about trails.

Unfortunately, with most modern cameras, the results above will probably produce elongated (oval) stars. If you examine them at 100% during processing, you'll find that you still have some trailing, rather than the pinpoint stars you were hoping for. This is because the rule was intended for use with film, while new, high resolution digital sensors record much smaller movements.

While you can simply adjust the number you use for the "500" rule to 400, 300 or 200, it's still guesswork. An improved method was developed, known as the NPF Rule. Here's how it reads: ( 35 x aperture + 30 x pixel pitch) ÷ focal length = shutter speed in seconds. "Pixel pitch" is the width of your camera sensor in mm, divided by the number of pixels in width times 1000.

Simple, right? Not really! As accurate as the NPF rule is, it's complicated enough to be impractical in the field. Many photographers have spent hours creating tables that can be used, but that's still something extra to carry. Our recommended solution is PhotoPills.

In the " Pills " section of the app, find " Spot Stars ". You then s imply select your camera model, lens focal length and aperture setting. You can then see the results of both the NPF rule and the 500 Rule. You'll be surprised at the difference. To be absolutely sure your stars appear sharp in a large print, use the result from the NPF Rule.

Aperture

Now that shutter speed is out of the way, we can discuss the other elements of exposure, starting with your aperture setting.

Obviously, the widest aperture (smallest f/number) available will allow you to gather the most light in the shortest amount of time. It's important to remember, though, that ALL lenses start to show the effects of diffraction as you approach the top and bottom of the aperture range.

Diffraction causes an overall loss of sharpness in your images. It's often recommended that you stop down one or two "clicks" from the maximum setting. Diffraction is minimized in Irix lenses, however, with the use of curved aperture blades. This means that you can go ahead and open your Irix 15mm up to f/2.4 without any major concerns. You may, of course, stop down by one "click" if you prefer.

ISO Setting

The final setting to consider for exposure is ISO. Since you've already selected the other two elements in the Exposure Triangle, this setting will determine the overall exposure value of your images. Determining the correct value is mostly a matter of trial and error, shooting and checking the result by previewing it. Knowing the basics of manual exposure, will help you determine a good starting point.

Keep in mind that if you're shooting with a crop sensor camera, noise will be more of a factor. For this reason, you may want to try to keep the ISO lower with a APS-C or similar sensor. Correct exposure is, of course, the most important part, so you'll want to consider the advantages of stacking when shooting with a crop sensor camera.

Overall, it's usually best to set your exposure toward the brighter side. This will help eliminate noise in the shadow areas that will become more obvious when lightening these areas in post processing.

Set it, start it and enjoy the evening.

We highly recommend using an intervalometer to capture multiple exposures. Not only does it facilitate stacking and creating time-lapse videos later, it leaves you free to enjoy your evening under the stars.

Many digital cameras now have on-board intervalometers that are very capable. For those that don't, you can find one online in the neighborhood of $20.00 that will do a very good job.

In most cases, you'll set your camera's shutter speed to Bulb, then set the exposure time on the intervalometer to the shutter speed you calculated earlier. Then, set an interval (the amount of time between shots) slightly longer than the exposure time. This gives the camera time to store each file. Leaving the number of exposures blank will tell the timer to keep shooting until you stop it.

Shooting this way, you'll often find nice surprise s in your images when you start processing. Meteors, planes, satellites and even clouds moving across the sky can add great interest to the individual frames. The lights from vehicles or other people may create dynamics in the foreground.

Just for fun, you can walk into your scene at some point and light yourself or point a flashlight at the Milky Way for a "star selfie". L ight up an object in the foreground while the shutter is open. Shooting this way gives you a whole range of creative options.

Processing Your Images

Because this updated guide is much more detailed than its predecessor, we'll be covering processing in Part 2. Meanwhile, here's hoping that this article helps put you on the right track to capturing those Milky Way photos you've always wanted.

Please remember that this is only a general guide. Feel free to use your own ideas, settings and creative licens e for your own images. Best of luck and we look forward to seeing your results!