Photographing the stars or the Milky Way at night isn’t all the difficult. However, unlike most other areas of photography, whether it be landscapes or portraits, the equipment makes all the difference in the world, and it can get pricey. The reason being, there isn’t a whole light to work with, so you need to bring in cleanly, as much of it as possible.
You accomplish this in two ways. The first being the camera body. A digital camera’s sensor is comprised of millions of tiny photo-sensors, which gather light and record an image. A full-frame sensor has larger photo-sensors that absorb more light. This increase in light means the camera can operate better than a crop-sensor in low light conditions and yields better image quality. It also means you can increase the ISO setting without increasing the noise, which is very important when photographing the Milky Way. Usually, a crop-sensor camera can take just as nice of photos as a full-frame camera, but this isn’t the case when photographing at night, or in low light conditions. When shooting the Milky Way, you need to operate around ISO 1600-3200, and a crop-sensor camera is going to have a ton a noise in that range. Even the full-frame has noise, but it’s manageable in post-processing.
Secondly, a full-frame camera won’t help you take better pictures of the Milky Way and the stars unless you also have a “fast” wide-angle lens. By fast, we mean a lens that can let in a lot of light to take advantage of the larger photo sensors. An example of this would be the Canon EF 16-35mm f/2.8L II USM or a Canon EF 24mm f/1.4L II USM. You really want a lens that can open up to f/2.8 or f/1.4, as this will let in a lot more light as compared to an f/4. I don’t want to debate the quality of the lenses, as each has its advantages and disadvantages. The bottom line is, you want a lens that’s 24mm or wider with an aperture of f/3.2 or larger. You can still take some nice pictures with at f/3.2, one once you go higher than that, you won’t get that real good glow from the Milky Way, nor will you pick up the smaller, more faint stars.
You’ll need a nice sturdy tripod and a cable release, or remote trigger capability. Exposure times will vary, but keep in mind, anything longer than about 25 seconds is going to capture the Earth’s rotation. As a result, the stars will start to appear oblong rather than dots.
Focusing can be tricky. Simply adjusting your lens to focus “infinity” won’t work. The reason being, the lens can actually focus beyond infinity such that nothing is in focus. You have a few options. The first is, go into Live View if your camera supports it, point the camera at a bright star, and rotate the manual focus to get the star to look as sharp as possible. If you have a Canon camera, while in Live View mode you can press the magnifying glass button twice to zoom 10x. This makes focusing easier. The second option is to take a picture, view it, zoom in as far as you can and see if the stars are in focus. Make an adjustment either clockwise or counter-clockwise with the manual focus, take another shot, and compare it to the first shot. This involves a lot of trial and error.
Here are some interesting specifics about the photograph shown at the beginning of this blog entry:
- It was a single exposure
- The clouds were light up orange by the small cities about 75 miles away
- I used a flashlight to “paint” the windmill during the exposure so that it would be visible in the photograph
- A little post-processing was done in Adobe Lightroom
Even with a full-frame camera, there is going to be noise at ISO 3200, so post-processing is important. You can minimize the noise, but you’ll never get rid of it without losing a lot of the detail. Cranking up noise reduction in Adobe Lightroom will remove many of the smaller stars and take away from the photo.