Along with my photo club friend, Bryan, who has a keen interest and much more knowledge of astronomy than me, we decided to try shooting the Milky Way.
When and Where
In the northern hemisphere, the Milky Way aligns itself the best for photography during the summer months. Shooting on a cloudless, moonless night is one of our criteria for going out and our timing is aided by the wonderful program Stellarium. It is a free open source planetarium that shows a realistic sky in 3D, in real-time, or in the past or future, just like what you see with the naked eye, binoculars or a telescope. This screen shot shows how the Milky Way can be seen from my location in the future on July 1 this year, rising up on the horizon from the SSE and angling up to the upper left corner. Another great free resource for locating objects in the sky is Sky Maps, and they post a free downloadable map of the sky every month with astronomical events to watch for.
Since having a very dark sky is important for shooting anything in the night sky, the challenge is finding a good location because of light pollution. Bryan and I have spent many hours driving around at night to find such a spot. A resource we have used is Blue Marble to help us find places around here that might work. It is a map of the world showing light pollution and can be zoomed in to almost street level with Google maps.
How to Shoot
- Shoot in Raw format.
- For white balance, use daylight or auto white balance (AWB).
- Use a tripod, level the camera, and shoot in manual mode, preferably with a remote shutter release.
- Use a wide-angle lens to capture as much of the sky as possible and focus on infinity. This is easier to do during daylight hours, remembering where that is on your lens.
- Use the widest aperture (the smallest f/number) so that it will gather as much light as possible.
- Composition – including the foreground adds interest. Take a test shot at a very high ISO to check the composition.
- Reduce the ISO to 3200.
- To eliminate star trails, follow the 450 or 600 rule for the length of the exposure. With my lens set at 16mm I start with a 30-second exposure.
- If your camera has long exposure noise reduction, turn it on. The camera will take a second exposure of equal length without the aperture being open at all so the second exposure will capture only the noise and then subtract if from the original shot. If your camera does not have this feature, you can do it manually. Put the lens cover on and take a second exposure of equal length. You will then be able to layer the two shots in image-editing software with the “dark frame” above the image layer and applying the Difference blending mode to the dark frame layer.
- Here, where there is a lot of light pollution the ISO often needs to be reduced by a full stop. Adjust the ISO and the length of the exposure until you get a good shot.
In Adobe Camera Raw or Lightroom, correct for lens distortion in the Lens Correction tab. In the Basic tab, increase both the contrast and the saturation to the highest (+100). The saturation boost will bring out the colors of the stars. I also add a bit of Clarity (+15) and Vibrance (+15). Make adjustments to the exposure and color temperature if you think it’s needed. In the detail tab, you can play a bit with the color noise reduction. Be sure to zoom in and out while making these choices to see their effect. These are not hard and fast rules, but a place to start.
Location! Location! Location!
The first shot was taken at the best location that Bryan and I could find around here last year. With the nearest, relatively small towns at least seven or eight miles away, our cameras still picked up on the light pollution. The second one was taken close to the shore of Lake Superior on the Upper Peninsula of Michigan. Both were shot with a 16-35 mm lens at 16 mm, f/2.8, ISO 3200 at 30 seconds and 25 seconds respectively. With the angle of view of that lens, the part of the Milky Way at the very top of the image was directly overhead. The camera “saw” much more of the Milky Way than what was visible with the naked eye on the first shot. On the second, that may have been the case also, but walking outside and being able to see this with my eyes thrilled me, something I cannot see with all the light pollution back home.
There are a few more astrophotgraphy tips that I posted about shooting and processing star trails that are also applicable with the Milky Way. That post is here.
This whole night photography assignment that I took on last year gave me the incentive to learn new skills and it will be a pursuit I will continue. For sure, Bryan and I will be roaming the countryside together in the coming months and years capturing star trails, the Milky Way, comets and other night sky wonders. We’ve only just scratched the surface.