I suppose the first thing I should tell you is that there are no "best settings" for night sky or long exposure photography. But while there may not be standard settings for every night sky image, there are some best practices, and I'll tell you where I normally start.
Use Manual Focus
One of the first things I do when photographing the night sky is switch my lens to manual focus. If you don't take this crucial step your autofocus will rotate back and forth forever and never allow you to actually take a photo. Once I've flipped the switch to manual focusing I usually set it close to the infinity symbol on the lens.
Whenever photographing long exposure images of the night sky, I like to have something of interest in the foreground. Ultimately where you set your focus depending on how far away you are from your foreground subject, or point of interest that you would like to have in focus. All lenses are different and yours may not have an infinity symbol so you will have to use trial and error in order to focus, or switch your camera to "Live View", use a bright flashlight or headlamp and shine it at your foreground object and rotate your lens back and forth until it comes into focus.
Long Exposure Settings
Your settings really depend on how dark it is where you are photographing. For instance, if it is a full moon versus a new moon your settings will be completely different. How much light pollution is there where you are? Which way is your camera facing? What time of night it it? All of variables come into play when deciding which settings to use.
But...here's a good place to start:
With a 16-35mm f2.8 lens
30 second shutter
If that is too dark I recommend only changing the ISO to a higher number if you are attempting to get a photo of the Milky Way. Increasing the shutter speed from 30 seconds could create "star trails" as the camera begins to read the Earth's rotation during longer exposures.
If that is too bright I recommend bringing down the ISO. You can also shorten the exposure by changing the shutter speed. Play around with your settings until you get a result you like.
Create images like this by stacking individual 30 second images together in the FREE software StarstaX
Gear You Need
Having the right gear for the job is important up to a point. While you can take night sky photos with some smart phones using apps like NightCap Pro, you'll probably want at least an entry level DSLR (digital single-lens reflex) camera. Decide what your goal is for the images. I.e. sell them to magazines and stock agencies, or simply post to Instagram. If you decided you would like to take professional level photos you will need a higher end DSLR. Depending on your camera body, you will also need a remote control release or an intervalometer. And of course, you will always need a tripod.
Here's the camera set up I use (click on the equipment name to find out more info about it):
Canon 5d Mark IV
Canon 16-35mm F2.8
Here's what I recommend for beginners:
Canon Rebel T7i, or
Canon 50mm F1.8
Here are other options if you shoot Nikon, Sony, or want to try out Sigma & Rokinon lenses:
Sony Alpha a7R III
Rokinon 14mm F2.8
Nikon 14-24mm F2.8
Sigma 18-35mm F1.8
Tamron 15-30mm F2.8
Tokina 16-28 F2.8
I've gotten a lot of questions on Instagram recently when I began posting a series of night images to my gallery. What are your settings? What camera do you use? What lenses are you using? How is the foreground lit? How is the background lit? You forget after a certain period of time the wonder and discovery of how to take a certain kind of image. One where you can't even begin to know where the photographer started. I always get so excited when people ask because I am so passionate about the art, and I love the whole process. But I want to tell them everything all at once.
"It's really simple," I say. "Settings are ISO 1600 f/2.8 for a single thirty second exposure. The tent is lit from behind where my boyfriend is holding a flashlight. My friend and I managed to stay relatively still for the time period." Ok, they think about it. But how does the f-stop relate to the shutter speed, and how do both of those affect the what ISO sensitivity to use?! AND...how long was the flashlight backlighting the tarp?
So let me break it down a little further, because I remember learning all this stuff mostly through trial and error, reading, and looking at A LOT of other photos. I'll describe each part of the exposure in relation to how I took the above photo.
There are three parts to exposure- ISO, Shutter Speed, & Aperture
ISO Sensitivity- For me, it was easier to understand ISO in relation to film photography. Back in the film days there were 100 speed film, 200 speed film, 400 speed film, etc... The higher the number the more sensitive the film was to light. For instance, if I were to photograph the same subject in daylight with all the same settings except different ISO sensitivities, the one with the lower number would be darker than the photo taken on the higher ISO. It works the same way with digital, but we don't have to use a whole roll of film with one sensitivity! We can vary it from photo to photo. You always want to use the lowest number possible in any given situation in order to avoid unwanted noise. In the photo above I used ISO 1600, which is relatively high, especially for my Canon Rebel T2i. This was one of the things that allowed me to capture the stars in just 60 short seconds.
Shutter Speed- I think this is the part of exposure that is easiest for most people to understand. The shutter speed is how long the shutter of the camera is left open during the exposure. The longer it is left open, the more light is captured. With this photo I left the shutter open for one minute. When people shoot on automatic during the day, their camera usually sets the shutter speed at a trusty 1/60 second. This is fast enough to capture most scenes (not sports or action) but slow enough to expose the image at a lower ISO. Because I left my shutter open for a minute I was able to capture a dark scene. So you might ask, Kat, why didn't you leave it open for two minutes and get more stars in the pic? I didn't do that because the longer you leave the shutter open, the more noise (grainy appearance to the photo) you get. To answer the question of how long Craig was behind us shining the flashlight? It was very brief, maybe a second or two. With a wide open shutter and aperture (which I'll talk about below) and a high ISO setting, we didn't need much light to create the above effect.
Aperture- Aperture is one of the most important parts of the whole puzzle, or I guess I could say one of the more expensive parts. Aperture is the same as f-stop. It is essentially how wide the hole in your lens opens during the exposure. Aperture does several other fun things too, but I'll focus on its role in general exposure in this post. My aperture was set to f/2.8 in the above photo. This is KEY! Most cheap-o wide angle lenses only stop down to f/3.5. Good enough to take kind of crappy star pics. The fact that my lens goes down to f/2.8 made a large difference in the quality of my photos. It opened up just that little extra I needed to take in the light necessary without using too high an ISO or too long a shutter speed.
Any more questions feel free to ask in the comments below!
Also I want to note that I called this post "The TAKING of an Image" not "The Making of an Image." As much as I love and admire Ansel Adams and his work, I think he was wrong. I'm simply an observer who strives to capture the beauty of every day. I didn't make anything in the photo above. I just borrowed it for a little while. Ok, enough of my two cents! :)
Kat Carney is an outdoor adventure photographer. She loves surfing, climbing, canyoneering, and mountaineering, and can often be found wandering around both the east and west coasts in her built out suburban. See her adventure wedding portfolio at www.swellandstone.com.