Photographing the Milky Way is remarkable because what you see on your camera is magnitudes more intricate than what you can visualize with your eyes. I was teaching a workshop in Montana the other day, and we took advantage of the big, clear, dark skies and it was so much fun to see people ooh and ahh over the images appearing on their cameras. With Autumn around the corner, it’s a terrific time to take advantage of earlier sunsets and cool clear skies before the winter makes it a lot more difficult to stay out at nighttime. Here are some tips to get you started making pictures of the Milky Way.
The Milky Way
The Milky Way is simply a thick concentration of stars. Our galaxy is a whole lot of stars and they have spread outward from the center in a disc shape. The Earth is part way out from the center on one side, so when we look at the night sky we can see toward the center of the galaxy and that’s the brightest area of the Milky Way–we’re looking through the thickest part of the cloud of stars filling the galaxy and that’s why it’s bright and dense. It’s also a powerful thing to sit and consider what you’re looking at. One of my students didn’t make any pictures at all that night–he just lay on his back looking upward, and I think he was the most satisfied of everyone.
The Rule of 600 for Mirrorless (Calculate the Crop!)
Remember, too, that the Earth is spinning and that makes the stars appear to move through the sky. You want your pictures of the stars to appear sharp and crisp, though, so you need to shoot fast enough to freeze their apparent motion. Or nearly freeze it. That’s where the rule of 600 comes in. Just divide 600 by the length of your lens and that will be the number of seconds you can shoot without having too much motion blur in your picture.
600/24mm lens = 25 seconds
So if you use a 24mm lens, you can shoot for up to 25 seconds and the stars won’t have very much motion blur. There are two caveats to this rule. First of all, it was made up for film photography, and many of our sensors and lenses now have much more resolution so the motion may be more apparent. You just need to practice to see how much movement you can personally tolerate. I recommend not pressing your nose up against the screen to see the closest possible view of your photograph. Think like my student above and simply enjoy the grandeur of the picture.
Secondly, this rule is based on 35mm film and sensors, so if you’re using anything other than a full frame camera, you need to convert for your lens first. If you’re shooting an APS-C sensor, like a Fuji or Sony a6000 series, then you need to multiply your lens length times 1.5 first.
24mm x 1.5 = 36
600/36mm = 16.66 seconds
That means your 24mm lens on your Fuji camera will allow for 16 seconds of exposure before the motion from the Earth’s rotation becomes very apparent. If you’re using a Micro Four Thirds camera, you need to multiply by 2 first. So, when I made the picture above with an 8mm fisheye lens, I first multiplied the lens time 2 to get 16, then divided 16 into 600.
600/16mm = 37.5 seconds
I only used a 20-second exposure, though, and there is practically no apparent movement in the picture. Just convert your focal length for your crop factor before using the rule of 600. Now, there’s a lot of other math you can do to totally eliminate the movement, but this rule of thumb is pretty good. If you’re getting too much movement, try using 500 instead.
Save Your Battery
Shooting at night with mirrorless cameras is wonderful. The articulating screens make it so much easier to see the display than with DSLR’s, and the batteries usually last longer than a DSLR in Live View. Still, you’ll find that your battery drains faster than usual. You’re making longer exposures than usual, you’re reviewing pictures longer, you may be using Long Exposure Noise Reduction, all of which use more power than you’re used to. One simple way to make your battery last a lot longer, though, is to disable the back LCD before you begin your exposures. Switching the view to the viewfinder will make your batteries last a lot longer since the camera won’t be projecting anything on the much larger and brighter back screen. Plus, your friends’ pictures won’t be affected by your screen’s light.
One powerful way to make your pictures of the night sky much more interesting is to include some foreground elements. They add scale and make a much better picture. You can include trees or structures or mountains. In my case, I was shooting on a mountaintop in a wide open field. I used trees on the horizon in the picture at the right, but I like even more the picture at the top where I used a Platypod Ultra sitting flat on the ground to allow grass to interrupt the sky for interest. Find something you can use to show the scale of the sky in your photo.
Photographing the Milky Way is fun. Remember to calculate for the movement of the sky using the right conversion for your lens, disable your back screen when you’re making exposures, and find some interesting foreground elements. Most importantly, take time to enjoy the grandeur of the universe bunched up before your eyes.
The Mirrorless Camera Maniac publishes each week–check them out right here.