As many questions as I get about photography, the one that comes up most is how to take great photos at night of star constellations, star trails, the moon, and the Milky Way. I went out shooting last night here in New Zealand and the above photo was the result. I wouldn’t consider it National Geographic quality by any means, but it gives you an idea what’s possible when then conditions are right. The conditions are really key to any landscape photography, be it in the middle of the night like this, or on the brightest of sunny days. You can do everything right, but if good ol’ mother nature isn’t cooperating, well, there’s nothing to be done about it.
This will serve as a general guide for any of you with DSLR or Mirrorless cameras. I can’t get into any specific camera models, so I’ll be assuming you know how to properly use yours. These are general guidelines and can vary based on your location, the time of year, the type of gear you’re using, and your experience.
For the image above, I went with 30 seconds. Because no moon was visible (that’s one of the variables I talked about), there wasn’t any ambient light. Not having a visible moon can be both a blessing and a curse. On one hand, you don’t have to worry about light pollution mucking up your image. On the other hand, it’s difficult to add any perspective to the foreground when it’s a pitch black night.
Depending on the camera you’re using, you likely won’t get much to work with on any exposure under 20 seconds. My advice would be to start there and add time if you need more light. If you get to 30 second exposures and still don’t have enough, step your ISO up to the next level.
The ISO settings will vary wildly between cameras. Some higher-end models perform well in low light by upping the ISO and not adding too much noise to the photo. For the above image, I used ISO 3200 on my Sony A7. However, if you have a Nikon D4, you might be able to pull off a similar result at ISO 2000. The more you increase the ISO, the more sensitive the camera’s sensor will be to light, but the more fuzzy noise you’ll add to the resulting image.
ISO noise isn’t entirely a bad thing for night photos though, especially ones like this. Noise contains detail, and when you’re looking for tiny stars to appear on a 6000 x 4000 image, one star might only be 4×4 pixels, and those 16 pixels don’t contain much light compared with the entire 24 million pixels in the photo.
Regardless of the camera you have, I’d recommend starting at ISO 1600 and moving up from there if needed. There’s another variable that may alter how you set your ISO: aperture.
Opinions on this vary widely, but I’ll tell you how I approach the f-stop number. Because a wider aperture (lower f/ number) lets more light reach the sensor, it makes the most sense to set it as wide as possible. With a wider aperture, you’ll be able to shoot with a lower exposure time (which means sharper stars and no streaking/trails) and a lower ISO.
However, the tradeoff here is dependent on your foreground objects and the kind of depth of field you’re wanting. If your foreground objects are relatively close to your camera and you shoot at f/4 focused on the foreground, the stars won’t be in focus. You’ll need to set the focus manually to infinity if you want the stars to be sharp as a pin. The narrow the aperture, the easier that is to do, but the lesser amount of light that actually makes it to the sensor.
Bringing it All Together
Hopefully by this point, you’ve started to see how all these settings work together. Crank up your ISO and you’ll be able to shoot at a narrower aperture. Slow down your shutter speed and you can lower your ISO or keep the ISO the same and widen your aperture. There’s a balance between all of these that you’ll just have to experiment with to find. Some cameras don’t have great high ISO performance, so you might need a lens with a wider aperture to compensate. Some lenses (like most kit lenses) aren’t incredibly sharp outside the center of the image at wider apertures, so you might need to compensate by cranking up the ISO and going to a narrower aperture to bring that sharpness back. (Are you thoroughly confused yet?)
I’d also recommend setting your camera to shoot RAW for night images. Because JPEGs are compressed by the camera, you’ll lose a lot of the light and detail data, which could make all the difference between a great photo and just a mediocre one. I screwed up on the image at the top of this post by shooting as a JPEG. I’d set the camera to shoot JPEGs for something else earlier in the day and just forgot to set it back to RAW. As a result, you can see the extra noise in both the lower corners and along the right side where the trees are. Had I been shooting RAW, I probably could have avoided that.
The ultimate goal is to have fun experimenting with what you can do with your camera and a clear night sky.
Get out there and have fun. If you have any questions or if there’s anything I might be able to help with, feel free to ping me on Twitter anytime: @mbchp.
[Source: Mike's Flickr]
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