Milky Way over Bear Lake II
Milky Way over Bear Lake II, Rocky Mountain National Park, Colorado
The best way to appreciate the immensity of our universe is to stand alone under a dark and moonless sky and contemplate the Milky Way. In an era of ever-increasing light pollution, many people have never seen the Milky Way, the diffuse band of light created by the hundreds of billions of stars of our own Milky Way galaxy. The Milky Way galaxy is shaped like a plate, not a sphere. We see the Milky Way when we look along the plane of the galaxy. The very brightest part of the Milky Way lies in the direction of the galactic hub, a mysterious region filled with clouds of gas and dust. I used two apps, Sun Surveyor and the Photographer’s Ephemeris, to calculate when the galactic hub would appear in the sky just to the right of Longs Peak as seen from Bear Lake in Rocky Mountain National Park.
I arrived in time to shoot sunset and scout the ideal location for the camera. I needed a place with a great view of Longs Peak, of course, but also a place where I could see Polaris, the North Star. To achieve the best possible quality in the image, I planned to use my iOptron SkyTracker Pro, a star-tracking device that counter-acts the Earth’s rotation. Digital noise is the great enemy of night photographers. Using a star-tracking device allowed me to make long exposures with low ISOs and still capture pin-sharp stars. Accurate tracking on the stars requires aligning the tracking device with Polaris. To further reduce noise and increase quality, I used Stack Modes. In brief, using Stack Modes requires shooting multiple identical images, then stacking the images like layers in a wedding cake in appropriate software. The software then drills down through the image stack at each point in the image and chooses the median value of all the pixels it encounters. This effectively eliminates noise.
To employ this technique for this image, I shot four frames tracking on the stars, then registered the stars and reduced noise using RegiStar from Auriga Software. Frames shot as the camera tracked the stars had blurry land, of course, so the next step was to turn off the tracker and shoot four stationary frames for the land. I reduced the noise in those frames using Photoshop’s Stack Modes-Median. The reflections of the stars moved, of course, just like the stars themselves, so I used RegiStar again to register and reduce noise in the reflections of stars contained in the good-land exposures. I then combined the good-sky, good-land, and good-sky-reflection shots in Photoshop. I shot all the frames with a 35mm f/1.4 lens, which gathers a tremendous amount of light per second of exposure. That, in turn, reduces noise still further. The final result of all this digital wizardry was an image that captured both the Milky Way and the land in rich detail, without the gritty digital noise that mars so many night images.