This past year I’ve been learning how to take and make star trail images. Watching the stars move across the sky has intrigued me for some time. To fan the flame, I have a friend that is heavily involved with astronomy and we’ve spent many hours looking through his telescope. With my love of photography and my growing interest in astronomy, I thought I would attempt taking some images.
In started to do some research online, I found many knowledgeable people online that share their tips and techniques. Here are a few I found helpful.
PetaPixel – How to Create Dazzling Star Trail Photos, From Start to Finish
Light Stalking – How to Photograph Star Trails: The Ultimate Guide
DIY Photography – Your Complete Guide For Photographing Star Trails
Enjoy this glimpse into my journey and some of the things I learned along the way.
1. Get Inspired
There are plenty of star trail images that can inspire you. This was mine. Redland’s photographer Steve Wormser is a friend of mine and he posted this image. I knew if he could do it, I could learn it.
2. Start Small
…or would that be start large? When I was testing my gear, I wanted the biggest thing I could find in the sky…and that was a full moon.
The next biggest thing I could think of was the big dipper. I set up in my backyard to try it out. You can see the big dipper moving across the California sky.
I ran my photos through the star trail software (More in Step 5 below) and discovered I started and stopped the process, bumped the camera and flashed on the backlight. But I was on the right track. I was excited the stars had made a circle…but at the time wasn’t sure how to replicate it in the future.
3. Find Dark Skys
One of the secrets of good star trail photography is finding dark skies, away from the light pollution of big cities. You also don’t want a full moon in the sky. Unless you are a real outdoorsman that knows their way around, one of the easiest way to find great spots is to connect with you local astronomy club and join them at their next star party. There is safety in numbers, and many knowledgeable people who can teach you about what you are seeing in the sky. I connected with the San Bernardino Valley Amateur Astronomers and headed out to the California desert.
4. Setup Your Camera
In addition to your DSLR camera, in order to take star trail photography, you’ll need a sturdy tripod, wide angle lens, intervalometer or some other method of automatically triggering your camera to take pictures. I am currently using a specialized cable and app for the iPhone called TriggerTrap. The have a great tutorial on how to the TriggerTrap App to take star trail photography. It’s definitely worth watching.
A 30-second exposure is needed to capture enough light. I put a 2-second delay in between shots so the camera has enough time to write the image to the camera’s storage card. Set the ISO fairly high (somewhere around 1600) the aperture as wide as possible (the lowest number you can get with your lens) to let in as much light and set the shutter speed to bulb. I suggest shooting in RAW format for the maximum flexibility in post processing. Check a sample shot or two before you start to make sure the image has proper exposure and your image is framed correctly. You can adjust the ISO, but be wary of adding too much noise into your photos. I set the maximum duration of 999, but stop the camera after 30-45 minutes of shooting. (If I know I’m going to be creating time lapse videos, I’ll shoot for 45 minutes. But most of the time I’m shooting closer to 30 minutes.)
To focus, set your lens to infinity, or if your lens does not have an infinity setting like mine, point your camera to the brightest star, then use the digital zoom to focus your camera. Here is a great blog post showing your how to focus your camera manually. Make sure your battery is fully charged and that you bring a spare. To help save battery life, turn your camera’s LCD brightness down and turn off the camera’s preview image. I use a Joby Gorilla type tripod to connect my iPhone to the tripod. I also have an extra USB battery to power the iPhone and use a few velcro cable ties to attach it to the tripod.
5. Setup Your Shot
For the most interesting star trail photographs, you’ll want something in front of the stars (tree building, rock formation, telescope, etc). I also prefer star trails that show the starts traveling in a circle or to show large star sweeps. To get these, aim your camera at the north star (also knows as Polaris). While there are many apps to choose from, I use the free Sky Map app. The stars will rotate in a counter-clockwise direction around the North Star. You can move your camera based on your desired composition.
There is not a lot to do when your shooting. Just make sure not to bump the tripod, and make sure that flashlight or cars light don’t unintentionally get into shots. Make sure you bring a chair…it’s a long time to stand! Since each final image takes 30-45 minutes each, take as many angles and compositions while you’re still awake.
6. Stacking Your Images
Once you’re home and you’ve transferred your images to your computer, there are several ways to stack your images to create your star trails. One method is to bring your images in as layers in Photoshop. PeachPit as a good tutorial on this method. The other way is with dedicated stacking software. The two most popular are both free:
The process with the stacking software is pretty straight forward. Load your .jpg images and hit OK. There are plenty of options to play with. Just use the basics to get the process started to see what you are working with.
Each stack take 5-10 minutes to create. You will start to see the star trails forming as the software begins to blend each layer into a single composite image.
Final image render.
7. Cleaning Up The Sky
It’s very common to get airplane trails in your images. For some purposes, this can be a neat effect, but most of the time you’ll want to remove these from your final image.
I make a copy of the entire star trails folder, just in case I make a mistake and need to get back to the originals. Open up the images in your favorite photo editing software, and simply draw a black line over the airplane trail.
You have to do this for every image that has an airplane trail. When you’re finished, run the new batch of corrected images through your stacking software. It’s very common to miss a few here or there. Take the time to go back and fix them. The results are worth it!
8. Meteor Or Satellite?
The darker the sky, the more airline and satellite trails you are going to capture. It’s common to mistake these for meteors. In fact, I was positive I had captured several during the Perseids meteor shower. But when I read the article Why Your Streak Is (Probably) Not A Meteor I started to take a closer look at my images to identify what WAS and what WAS NOT a meteor. The big tell is to look at several images…if the image continues in the second shot, it’s a satellite.
I was so pleased to find I did capture one shot a Perseids meteor. Notice both ends taper and the color shift in the middle.
9. Rookie Mistakes
“If at first you don’t succeed, try try again.” This is especially true when it comes to star trail photography. With all photography, it takes thousands of shots to become proficient. Out of 100 shots, were lucky to get 2 or 3 we’re really proud of. With star trail photography, you’re limited to the number of completed images in an evening…6-10 would be considered great. Don’t get discouraged if you don’t get it the first couple times. Here are shots of my “learning experiences.”
If you can set up your equipment while there is still daylight, that is best.
10. Check Lists
It would be a real bummer to get all the way out to your destination and find out you left some vital piece of equipment back home. Here are a few checklists I’ve found helpful in prepping for your star trail journey.
BEFORE YOU LEAVE
[ ] Snacks
[ ] Caffeinated Drinks
[ ] Trash bag
[ ] Paper Towels / Hand Wipes
[ ] Directions (printed in case cell phone coverage is not available in remote areas)
[ ] If you are meeting someone, having their cell phone can be handy in case someone is delayed.
[ ] Appropriate Clothing
[ ] Flashlight (make sure you use red light and follow star party etiquette if you are shooting with astronomers)
[ ] Folding Chair
[ ] Sleeping Bag / Tent (if you are staying overnight)
[ ] Cash for incidentals
[ ] Camera
[ ] Fresh Batteries
[ ] Wide Angle Lens
[ ] Tripod
[ ] Intervalometer / Trigger Trap
[ ] USB Battery for iPad
[ ] Cables and Connectors
As you may be able to tell from this video, I’ve really enjoyed this unique aspect of photography and look forward to my next star party!
The heavens declare the glory of God, and the sky above proclaims his handiwork. (Psalm 19:1 ESV)