Photographing the Milky Way

Photographing the Milky Way was something I wanted to try because with the naked eye it’s barely visible here in Finland. You can see only a dim cloud-like area in the sky but that’s all. So, let’s get out and try. A camera has a much better low light sensitivity than the human eye. At least better than my eyes. With a long exposure, you can catch a lot more light than what the eye can see.

Equipment for photographing stars

You need a sturdy tripod, a camera with manual controls, a lens with a short focal length, and a wide aperture. That’s all. The camera should have good image quality even with a high ISO. A remote shutter release can help reduce camera shake but you can use other techniques too.

How to expose for stars

Ok, with a decent camera you can use a long exposure time and catch more light. This is an advantage compared to the eye but it has its disadvantages too. First, you should notice that the stars are not stationary objects! No, we are all traveling on a spinning rock through the vast space. Because of this, the stars will appear as lines (star trails), not dots in an image. That happens actually with quite short exposure. So, how to expose?

The principle to photograph stars like this is to use a wide-angle lens, large aperture, and short enough shutter speed. Because the shutter speed and f-stop values are kinds of constants because they can vary only a little, you control the exposure by changing ISO.

The shutter speed with ‘500 rule’

The shutter speed should not exceed 500 divided by the focal length of the lens used. In my case, the longest recommended shutter speed is 35 seconds as I used a Nikon 14 – 24mm f 2.8 lens (@14mm). The 500-Rule is 500/14 = 35.714. I actually used a shorter time, 20sec and 30sec because I think the stars start to leave trails soon after 20sec.

It is this easy. I tried different combinations with shutter speed between 20 and 30 seconds, f-stop 2.8 and 3.3, and ISO 2500 to 4000. The Milky Way became clearly visible but not that bright as I have seen from other photographers. After a quick edit in Adobe Lightroom, it looked like this. Not as good as I wanted but OK for my first try.

Milky Way photographed in Finland
The Milky Way