Tutorial - Astrophotography Basics

Point that glass up to the stars and catch the beauty of the great beyond!

There is nothing quite like sitting high up on the mountains late at night and staring up at the millions of stars blanketing the sky. Though beautiful and incomparable to the human eye, a camera's sensor can pick up a lot more light, revealing even the faintest of details.

In this tutorial, I'm going to go over some basics on how to get your camera to accomplish this. This will be mostly about just being able to capture the stars in a landscape photo, a great foundation for the rest.

To start, let's talk about gear...

GEAR:

I very much enjoy believing that gear doesn't make a photographer, but when it comes to astrophotography, some stuff is gonna work and the rest just isn't gonna cut it. For the most part, any DSLR will work fine. While some sensors work better than others in low light conditions, it mainly will come down to the lens. You're lens should have the capability of having a fairly wide open aperture (The wider it is, the better! Wider = more light coming in). A good rule of thumb is to use a lens that has an aperture of f/2.8 or wider. If yours isn't able to open this much, your going to run into issues of bringing in enough light without significant star trailing (We'll talk about what that is in a bit).

A setup for deep-space astrophotography.

So for the most part, if you have a DSLR and a lens capable of opening wider than f/2.8, you're good! Optionally, though extremely helpful, is a sturdy tripod. I've done tons of pictures where the camera was propped against a rock or something and it came out fine, but a sturdy tripod is unbeatable and saves some stress.

So let's get into the actual photography...

Setting up is important. If you live in Seattle and walk out your back door to try this... it ain't gonna work too great. So get yourself out high in the mountains, bring a warm blanket, and some nice late night snacks. Find a nice vantage point and set your camera up to capture everything you want in the shot (Maybe some mountains blanketed by stars?). Once that's ready, let's start working that camera.

FOCUSING:

First, you're going to want to get focused on the stars. A good way to do this is to set it to a high ISO and turn it onto the electric view finder while predictable exposure is turned on, where it locks up the mirror and displays what the sensor sees on your rear LCD. Find a star and zoom in on it through the EFV as much as you can. Here, you can finely manually focus (And keep your camera/lens on manual focus the entire time!) until the star is not a blur, but rather the smallest spec you can make it.

Now that the stars are in focus, lets talk about settings...

SETTINGS:

Settings can be wonky depending on the lens and camera you are using. A general rule of thumb that I use for settings is 15 second exposure, f/1.8, and ISO 800. Now, this changes depending on the lens' focal length and widest aperture. The greater the focal length, the more star trailing you're going to see on a long exposure. Star trailing is when the exposure is so long, you can see the streak of the stars as the Earth rotates. A 50mm lens and a 15 second exposure will see this quite well. (But be creative! Star trailing can make for some cool pictures, something I'm working on still!) A wide lens such as a 20mm can go for about 20 seconds before star trailing becomes an issue (Again, this depends on the DSLR body, some preform better in low light).

An example of star trailing from a long exposure.

So play around based off of those first settings. Mainly the exposure and ISO. You want to keep the aperture as wide as possible and also try to maintain the ISO as low as possible. The ISO can be adjusted to compensate for an increase of shutter speed to avoid star trailing (If that's not what you're going for.) Remember... the higher your ISO, the noisier your image. This can be particularly problematic for these shots.

Oh... AND SHOOT IN RAW!

Astrophotography is all about bringing in faint details in the form of data. RAW just has a lot more data to work with, and to bring out these details, the data is going to need to be enhanced.

So lets talk about that, enhancing it...

ENHANCEMENT:

You've got your picture of the stars now, and it looks awesome already! What if I told you; you can reveal even more with a little work. I personally use lightroom classic to do this. Some prefer photoshop or even other software, but each has their pros and cons depending on the type of photo you're trying to edit. To me, for a simple landscape star shot, lightroom is the most efficient.

Do what you normally do with any other photo in lightroom, play around! You'll see what brings out the stars more, what enhances the sky, and what is just "too much!"

There are some who act like editing photos is sacrilegious. I'd strongly disagree. This is your art, make it how you imagine. Perhaps some people may enjoy a raw unedited photo while others prefer to make a completely made up composite image. It's art, and by definition, is subjective.

Let's take a few steps back real quick to hit on something, planning...

PLANNING:

Do you want to ensure the milkyway's rim or core is in your photo? Maybe you want it rising right above Mt. Rainier like it finally erupted... just stars instead of fiery death. Well, this isn't always feasible at your will. The location of the stars in the sky at certain times changes. As well, you need to understand the vantage point you will be shooting from (think cardinal directions). A fantastic piece of software I use for this is "stellaris." Check out this software (or similar) to understand where the stars will be throughout the night so you can imagine how you will be shooting.

Also consider light pollution. You can be MILES away, but Seattle's (CURSE YOU) light pollution

can still make a "orb" in the sky if you're facing that direction. Realistically any largely developed areas.

Weather... that's a big one but fairly obvious. Not going to much to shoot if it's raining all night. Consider the moon with this... A full moon will brighten the sky drastically, hazing up the stars.

A quick bit on focus stacking...

FOCUS STACKING:

Something you may notice is that the foreground (For example, the mountains) are not in focus. Well... that's because you were focused on the stars! A way to combat this is to take another photo of the foreground (focused on it) and edit it in photoshop to put the in-focus foreground in. Combining layers of focus to form a cohesive image is called focus stacking.

What next?

Aside for now wanting to get out absolutely every clear, dark night? Well there's plenty more to do with the stars! Unfortunately this usually requires the commitment to more gear. Using something like a star tracker can allow your camera to follow the rotation of the Earth.

This can let you get some INCREDIBLE detail of the

milkyway and eliminate star trailing. It can also be used with a telephoto lens of telescope to photograph deep space objects! I'll make a tutorial on that in the future.

Otherwise, get out there! Enjoy the beauty of this expansive world we are in.