Star trails at Dunluce

Behind the scenes in the creation of this star trails photo.

Another 'photographic first' ticked off my list this summer - here are my first star trail shots! After waiting for weeks since my climb up Binnian for another clear night, there was something of a window of opportunity last night. The sky wasn't exactly cloud free, but it was the best we'd had in a while - plus there was the added bonus of perhaps catching the tail end of the annual Perseids meteor display that had been resolutely hidden behind cloudy skies over the past few nights.

The Shoot

Cue a trip out to my favourite castle at Dunluce, hoping the clouds would stay away and I would be able to experiment with my shots. I brought my kids too, plus a blanket to lie on, pillows to cushion our heads as we lay back for the best star gazing position, and snacks to enjoy as the midnight hour approached.

My research on star trail photography had suggested using multiple 30 second exposures and stacking them later in post production rather than one long exposure (the latter approach tends to produce a lot more noise in the final image).

So I got in position and focused on a far distant light in Portrush and made sure I knocked off the auto focus on the camera once I'd done that. Shooting in full Manual mode, I wanted 30 second exposures (the longest the camera can do by itself) and opened the aperture up to f/2.8 to let as much light in as possible. Then, it was a matter of experimenting with ISO to get the exposure right. As the moon rose just shortly after I started shooting, the foreground of the castle was nicely light painted for me. Plus the last remnants of twilight to the north meant the sky wasn't totally black, so exposure was quite easy to manage and I ended up shooting at ISO 1250. 

After that, the main bulk of the work was done. In this case, I used the Intervalometer on the camera to set the number of shots I wanted (75 in total) and to allow a 10 second delay between each one to make sure the sensor didn't heat up too much. I pressed the button and lay back on the blanket to enjoy the meteor show (I saw 3 of them), enjoy the midnight snack (which seemed to consist mostly of fruit, interestingly enough) and make magic memories with my kids. Through the night, we saw a few meteors (around 5 or so in total), something tremendously exciting when you're the age of my kids, and ate probably one of the healthiest midnight snacks in history. As the shoot went on, cloud began to build more from the north and we finally called it a night just after midnight.

Post Processing

As I shot in RAW, I did the first batch processing in Lightroom. This mostly consisted of increasing the Clarity a bit to pull out more stars and bumping up Luminance to reduce noise. The only other processing was to reduce contrast overall by reducing Shadows and Highlights. All the adjustments were relatively minor.

Having exported the shots, I experimented in processing them in two ways.

  • Firstly, I downloaded some wonderful freeware software called StarStax. It's very easy to use and the processing is very quick. I had to experiment a bit with the number of pictures to include - the shots towards the end were very clouded out and the Lighten Mode you use in StarStax layers these clouds up on top of each other.
  • Secondly, I used Photoshop. I loaded all the shots as layers into one file and set the Blending Mode to lighten. Low and behold, just like in StarStax, the star trails appeared - as did the clouds. What PS allows you to do, however, is add Layer Masks to allow you to paint out the clouds on each image where they are found. 

Overall, Photoshop was more flexible - but a lot more work! If there were no clouds about, I think I'd be more than happy to use StarStax. It's a fabulous piece of software - especially as it's free!

So that's another first done. I'm looking forward to experimenting more with star trails as we get into the autumn nights. If you want to keep improving as a photographer, I'd urge you to make your own list of 'firsts'. Challenge yourself, experiment away, make your mistakes, learn from them. And make sure you pack a warm blanket and a fruit picnic if you're out chasing some stars...

Bonus Content

One of the added benefits of doing star trail shots is that you end up with a bunch of images, just crying out to be turned into a timelapse video! So here you are - you can see the clouds building as the evening went on.