5 Simple Steps to Use When Photographing Stars and Star Trails
Have you tried photographing stars and star trails and ended up frustrated? We’re going to fix that. I was recently on vacation at the family cottage, where I had unlimited time to experiment, so I did just that! I spent several nights photographing star trails, so now I can walk you through all the steps you’ll need to take star trail photos!
An Unplugged Vacation Leads to Experimentation!
You know what an unplugged vacation is, right? The unplugged vacation means no phone, no wifi, no technology of any kind. My in-laws have a beautiful cottage on a small lake about two hours from our home. Every couple of years, we get to spend some time at the cottage recuperating from the stresses of daily life.
I mostly love it, but I’m gonna be honest here and admit that I also really love my technology. It is hard, hard, hard to give it up for a week! I console myself with the one technology that works up there in the boonies: my camera! This year I chose to learn how to photograph star trails, and now I’m going to share my best tips with you!
When you think about Photographing Stars, you might begin by thinking about your camera settings. In actuality, prepping in advance for photographing star trails is an essential part of nighttime photography. You will need to do some pre-planning and even a wee smidge of math, but you will be so happy with your result it will be worth it!
Step 1 – Photographing Stars
Location, Location, Location
As you might imagine, the next important step in photographing stars and star trails is location. You will want to find a place that has a low level of light pollution. If you doubt how much light pollution is in the area where you’d like to shoot, check a dark sky map online to see where the darkest location is near you.
Now that you have found the right location, check it out during the day to plan out your image. A compelling picture of the night sky has something showing in the foreground. Choose an object such as a lighthouse or a barn, or go with whatever you have handy, like a flag or a nearby tree.
Step 2 – Photographing Stars
Once you’ve staked out the perfect location for where you will be photographing stars, you’ll need to make sure you’ve got all the proper equipment packed. You will most likely want to use your widest lens to capture as much sky as possible. I love my Tamron 15-30. I love that it has a lens hood built right in, so I have one less piece of equipment to carry.
You will also need to know if your camera has built-in time-lapse or intervalometer settings. I shoot with a Canon EOS R, which does not have this setting built-in, so I use an external intervalometer. An intervalometer allows you to set up your length of exposure, how many shots you’d like to take, and how much time elapses between each shot.
Once you have it all programmed, you can hit PLAY and let the camera do the work for you! You will want to set your intervalometer to take about 200 photos with as little time as possible between shots for star trail photos. If you take more photos than necessary, you can choose which ones you’d like to use and discard the rest. Better to have too many images to work with than not enough.
If you don’t already have a tripod, photographing stars gives you the perfect excuse to invest in just the right one. A tripod is a critical piece of equipment for star trail photos. I adore my Peak Design Travel Tripod. It is easy to set up, lightweight, and maneuvers super easily in the dark.
Since you will be taking many shots when you’re photographing stars, you’ll need to be sure to have a memory card big enough to hold a bunch. I have had a great experience with these Lexar Professional memory cards. They are reasonably priced, speedy enough at 250MB/s, and I haven’t found a photoshoot yet that won’t fit on a 128GB card! Watch for special deals around Black Friday or Amazon Prime Day to stock up!
Finally, be sure and pack a spare battery or two for your camera, all charged up. And be sure to bring fresh batteries for your intervalometer as well. I can tell you from experience that arriving at your site thinking you’re ready for photographing the stars, only to discover your battery is half-charged, is going to leave you with a whole lot of feelings, none of them good!
Step 3 – Photographing Stars
Research Your Settings
You know the location where you’ll be photographing stars, and you have the equipment you need. Now it’s time to talk settings. When you’re shooting at night, it is annoyingly easy to get a grainy image. There are a couple of things you can do about that. First, I recommend keeping your ISO as low as possible. I prefer an ISO of 100 for nighttime shots. However, when photographing star trails, it can be tricky to keep ISO low and still capture the detail of the night sky. I mean, with the sky so dark, you need to be able to let in light however possible. If you keep your ISO at 100 and dramatically increase the shutter speed, you will get blurry stars that already show bits of star trail.
Any photographer can capture naturally occurring star trails using a long shutter speed. However, your overall photo quality will not be as sharp as if you stack many single images. Stacking allows you to raise your ISO, keep your shutter speed low, and combine a whole bunch of images into one amazing final image of star trails. But I’m getting ahead of myself. We’re going to talk more about stacking in step 5. For now, know that instead of taking one photo with a long 30-45 minute exposure, you will be taking many, many images and using them together.
More Reasons for Stacking
If you need more reasons to stack instead of using one long-exposure image, here are some drawbacks to photographing stars in this way. First, you will end up with more noise on a single exposure. Combining multiple images will reduce this problem significantly. Second, by shooting one long exposure, you lose your option to take a quick test shot, re-frame or tweak settings and shoot again. If your shutter is open for 30-45 minutes to get the star trails you want, tweaking is a challenge and can make for a very long shooting process. Finally, you can be more creative in your editing by stacking multiple images.
Now that I’ve convinced you that photographing stars is best done with multiple images let’s get back to the important business at hand. Set your ISO around 3400-6400 as a starting point. You can and will need to tweak that a bit to fit the conditions in which you’re shooting.
Open your aperture as much as possible (small #). I set mine at 2.8 because that is the widest setting on my 15-30. You should open yours as wide as your lens will allow. Some lenses go as wide open as 1.4. If you have that lens, go ahead and take advantage! Aperture is the easiest way to get as much light as possible into your lens for nighttime photos.
Next, let’s talk about shutter speed. To determine where to set your shutter speed, you’ll need to do a wee bit of math. Don’t worry. You can do it! First, refer back to the lens you’re using. Take the focal length at which you’re shooting, and divide it into 350. For example, I’m shooting at 30mm, so the math looks like this:
350 divided by 30 = 20.59
Since you cannot set your shutter speed at precisely 20.59, go ahead and round that to the closest setting. Now you have a base number at which to begin. You will fine-tune this number when you’re on-site but take note that this is only your starting point, and you will end up making a few adjustments. After a few tweaks, I ended up setting my shutter speed at 23. If you’re forgetful like me or nervous when you arrive at your site, take note and write these #s down now. Tuck them into your camera bag, so you are ready when you get there!
Step 4 – Photographing Stars
Pre-shot Plan and Setup
You are now armed and ready to put that camera to work photographing stars! Be sure to arrive early at your location. You will want to set up your equipment while there is still light. It is much easier to get your tripod in place when you are not fumbling around in the dark. Once you have your camera up, your intervalometer attached, and are ready to frame your image, take a look around. Find the clearest view of the sky, and don’t forget that object in the foreground.
Take a Foreground Shot
After the sun has set and the sky begins to turn beautifully blue (aptly called blue hour), take several shots of your scene, focusing on the foreground and the barn, rock, or tree that will show in the final image. You will want these images later to blend with your sky, so you can make out details of what’s in the foreground.
Be sure and take a peek at your image and check that your horizon is straight and everything is just where you want it. Once you have everything set, your camera is level, and you’ve captured your foreground, keep your camera right where it is! It’s important not to move anything now because you’ll want all of your images to line up perfectly when you process your star trail photo.
Check Your Focus
You are getting close to photographing stars now! You will want to focus your camera like a laser! The best way to test this is to set your lens on manual focus and move your focus ring to the infinity symbol, which looks a bit like a sideways number 8.
Photographing Stars gives you the perfect opportunity to use focus peaking if your camera has that feature. As soon as you see the first couple of stars blinking at you from above, turn on your camera and use the LCD screen to zoom in as close as possible to one of those stars. If your camera has a touch screen, use the pinch maneuver to do this.
Focus on one of the stars you see above using the red digital focus assist on your LCD screen. If the focus is a bit off, go ahead and turn the manual focus ring on your lens to fine-tune. Once you get focus perfected, hands off the focus ring! You can use a small piece of blue painters’ tape to hold that focus ring in place and serve as a visual reminder not to tinker with your lens as you shoot. I’ve learned this lesson the hard way.
Fine Tune Your Shutter Speed
Now you have your focus set and your settings ready to roll. Before you take many, many shots back-to-back of star trails, you’ll want to be sure that the shutter speed you calculated earlier will be perfect. Take one quick picture. Peek at that photo on the back of your camera, zoom in as much as possible and make sure the stars you see are round and not oblong. If they are oval or oblong, you may need to adjust your shutter speed a little faster. If the sky around the star is too bright, you’ll need to change your shutter speed to a little slower setting. Now is also the time to fine-tune your ISO a wee bit.
Step 5 – Photographing Stars
Stack Your Images
When you have finished photographing stars and have at least 100 images, it is time to figure out what to do with them.
For circular star trail photos, you will want to use a technique called stacking. Stacking uses multiple images layered atop one another. Combining multiple images will reduce noise and result in one beauty of an image with crisp detail and very low grain. The best part of stacking is that there are plenty of free software programs available. The program I use is called Sequator, and it is available HERE for free.
Once you have your stacking program up and running, it is relatively simple to load up your images and allow the software to do the rest of the work. I used 144 images taken at ISO 1200, 17mm f/2.8, and 23-second ss for this image.
My friends at Improve Photography have a great post on using Sequator to stack astrophotos and reduce noise. Check it out for specifics on how to load images and what settings to use to get you the result you desire! Here is a screenshot of the settings I used for my star trail photo.
You will notice a few differences between this image and the final version shown above. Once the merge is complete, I brought the image into Lightroom for some color adjustment and then into Photoshop to straighten some of the skewed lights along the waterline of the lake.
Wrapping It Up
Now that you have the basics down, you’re ready to get out there and practice photographing stars and star trails! Be sure and share your images over in my Facebook Group.
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