If you have not studied the night sky in depth it can be overwhelming to know when is the right time to get out to create the photographs you envision in your mind. There are many factors to consider before entering the wilderness. Earth is constantly rotating along its axis and orbiting around the sun while the Milky Way is ever-changing in our sky. The good news is that it is consistent from year to year. With technology, all of this information is easily accessed with the amazing device we now call a ‘phone’, or on our computers.
Selecting a Location
Having an interesting foreground is critical to creating a nightscape that is memorable. Photographing the Milky Way on its own will get you excited initially but without a foreground it is just another photograph of the Milky Way that anyone with proper skills could capture.
Good foregrounds are anything that would also make a good landscape photograph: mountain scenes, interesting rock formations, sand dunes, the ocean, etc. Unfortunately, you cannot take nightscapes just anywhere – you must take light pollution into account. Our modern lifestyle has littered the skies with a glow that has made the stars all but disappear in cities, especially if you live in heavily-populated areas like the east coast of the US or mainland Europe. You may need to travel long distances to escape our collective efforts to destroy darkness.
Fortunately, there are some great tools to help you find dark skies, the most useful is Dark Sky Finder, which is now built into the Photographer’s Ephemeris when you enter night mode. It is best to be in areas where the map is black or dark grey but good photos can also be created in the green zones.
Some of my favorite national parks with dark skies:
Selecting the Season
If you have a trip planned for the desert in December and hope to capture the Milky Way core you will be sorely disappointed. In the northern hemisphere, the Milky Way is well below the horizon at night in December and January. When I started photographing the night sky, I struggled understanding when the Milky Way would be out and what it would look like.
There are 3 different ‘looks’ the Milky Way can have: The ‘Arc’, ‘Typical’, and ‘Vertical’. Each are demonstrated below:
The Arc Milky Way is visible in the spring, Typical is visible in summer, and Vertical in the Fall. You can also find some of these intermixed at different times of the night. The chart below shows when each is visible. These are general guidelines for mid-latitudes in the northern hemisphere at the middle of each month.
If you are traveling far north, take into consideration the midnight sun, which is when the sun is out 24 hours a day in the summer. Also, in the Southern Hemisphere the Milky Way looks very different so be sure to do your planning before you hit the road. The same tools (TPE and Stellarium) can be used by changing the location in the apps.
Shooting a Southern Hemisphere Milky Way
To find out how the Milky Way will look at a specific time and location you will want to use planetarium software like Stellarium, which allows you to input your desired location and time to see exactly what the sky will look like. There are many pieces of software and apps for your phone that achieve the same thing. I cannot recommend using Google Earth for this task, as the night sky is inaccurate.
If you are already in the field at your location and want to know where the Milky Way will be in the future, you can use the Photopills app in Night AR mode. When you point your phone at the sky it will show you an overlay of the night sky with your camera on. You can then change the time and date to plan out future photographic opportunities.
The Photographer’s Ephemeris, or TPE, also has a Milky Way tool built in that shows you a 2D representation on the map of where the Milky Way will be and its orientation.
Planning Around the Moon Phase
Generally, when photographing the Milky Way you will prefer a new moon and you will be best served by planning your trips around this time of the month. Start by looking at a moon phase calendar to determine when the new moon will be. Shooting 4-5 days around this date are generally safe for a moon that is dim enough to not wash out the sky.
You’ll extend your your shooting days by paying close attention to when the moon rises and sets. When the moon is below the horizon, the sky is just as dark as during a new moon (except near a full moon). The best tool for figuring this out is TPE. You can quickly see when the moon rises and sets, along with the position of the Milky Way (night mode is currently only for iOS). You can also use Stellarium to see when the moon is setting.
Checking the Weather
Cloud cover can quickly ruin your plans. Solar Eclipse Weather shows the average cloudiness for each month. I would avoid the Pacific Northwest in the spring. The southwest desert, however, has very little cloud cover year round. When the time comes to do your night photography, always check the Clear Sky Chart for that evening.