The burning question
And now, the answer to the question that’s been on your mind, and the one I get asked everywhere I go: What settings do I use to take a nightscape?
To answer that question, we must ask another one first: What kind of nightscape will you be shooting? For brevity, I’m going to focus on the most basic nightscape, a single exposure. Stacked images, panoramic, and long-focal-length nightscapes involve another level of technical complexity around topics like image registration, masking, nodal points, parallax, stitching, and tracking hardware. It would take quite a few more pages to cover them all adequately.
Earlier, I talked about the trade-offs in nightscapes between image quality and light gathering. When deciding on your camera settings, this is where the rubber meets the road. If you want lower noise (less grainy images), use a lower ISO value. Unfortunately, this comes at the expense of light gathering.
If you want better details, especially sharper stars at the edges of your images (less coma), close down your lens a few f-stops from wide open. But again, this comes at the expense of light gathering. Likewise, if you want more pinpoint stars across your entire field of view, you must shorten your shutter speed.
Before getting down to brass tacks on the settings for a single exposure, there’s one critical thing to address: Don’t forget to focus! Focusing nightscapes can be a challenge because you are working with a wide field of view and almost no light. Most autofocusing systems fail in darkness. They won’t give good results, so turn off autofocus and get good at focusing manually.
Here are two tips for better nighttime focusing. First, focus your camera in daylight. Mark the lens with tape where your infinity focus is sharp. Or, better yet, just tape the focus ring down. Second, use the “live view” mode on your camera if it has one. With live view on, rack your focuser all the way out to get to rough infinity focus. Point your camera at a bright star and then zoom into it. Gently move the focus in and out until the star becomes as tight as possible. You can tell when you’ve reached excellent focus because even the faint background stars will “pop” into view.
Now you’re ready to take a nightscape. The best way to start is to go all-in on light gathering and see your results. From there, you can experiment with aperture, ISO, and shutter speed. Start by opening your shutter all the way. Crank up your ISO — try 6400 or even higher. Apply the “500 Rule” for your shutter speed: Divide 500 by your lens’ focal length, and the result is a decent estimate of how long you can keep your shutter open before stars will show trails. Take a few shots. Change your settings. Take some more shots. Don’t be afraid to experiment; you probably have plenty of room on your memory card. Test out all sorts of values. When you get back to your computer, take the time to evaluate what works best for your camera and for your personal taste.
Regarding the computer, I would highly recommend that you use Adobe Lightroom for organizing, evaluating, and editing your images. Keep in mind that all nightscapes will have some noise, some distortion, and probably a bit of star trailing. While I won’t cover them now, rest assured there are advanced techniques, such as image stacking and focus stacking, that can dramatically improve the noise signature and edge-to-edge sharpness in your nightscapes.
Early on, your goal should be to decide what is acceptable to you. As you gain more experience with your artistry, gear, and techniques, you will begin to intuitively set up the camera for the type of shot you are taking. There will be failures; that’s how we learn. I hope, however, that your initial triumphs in capturing nightscapes will keep pushing you to do even better, night after starlit night.