Summer is a great time to dive into astrophotography, especially if you’re looking to capture the Milky Way. And of course, clearer skies and warmer nights help, too. We’ve been excited by the release of the first photos of Pluto, and it’s given us the itch to photograph the night sky. Luckily, astrophotographer extraoridinaire Aaron Harris was happy to share his tips and tricks for photographing the International Space Station with us, and that means we can pass them on to you!

Transit of the International Space Station and the sun by Aaron Harris using Triggertrap Mobile.


Hey Aaron, tell us a little bit about yourself.

I'm a husband and father of three living in Bowling Green, KY who is a Unix geek by day. Other things I enjoy are tracking the International Space Station, cooking wood fired pizza, taking photos of things you can't see, and staring at the sun.

How does photography fit into your life?

I work on servers all day and there isn't much creativity in my line of work, so photography is my creative outlet. I love using the camera as a tool to show something that cannot be seen with the naked eye.

What first got you interested in astrophotography?

In college, I had an astronomy lab where we took photos of stars at various exposures. I don't remember a thing about what we had to calculate, but I do remember the 5x7 prints. The different colours of the stars, the different brightnesses, the different lengths of the trails, all of it blew me away. Years later when I got a DSLR, one of the first things I did was point it up at the sky. I haven't looked back.

Astrophotography does take some forwarding planning, and a fair amount of gear!

Astrophotography does take some forwarding planning, and a fair amount of gear!

Do you capture any other astronomical events other than ISS transits?

I love taking 180° fisheye shots of the night sky, especially when the ISS or any other satellite is streaking across the sky. I also capture sun spots, the occasional star trail, and I take mediocre shots of the planets.

How many years of research did it take for you to get the ISS transit shots that you do now?

A few months after getting my first DSLR, I took a horribly composed shot of the ISS in my backyard. A transit shot was something I wanted to capture, and it took about a year of planning, waiting, giving up, and more planning until I finally succeeded in 2013. The idea to use Triggertrap just hit me one day after seeing a blog post about using a sound emitted from a phone to activate the shutter. After a trip to RadioShack (RIP), and a little bit of coding I had it working perfectly.

So how often do ISS transits happen?

They actually happen daily, as long as you are within a three-to-six mile wide strip that's 12,000 miles long. That being said, since January there has only been one transit visible over my house. That's why I expand the search to 100km. Once you do that there is usually at least one transit of the moon, sun, or planet a week in that radius. Out of those, there will be maybe one a month that will be worth attempting (weather permitting, of course). You can use the CalSky website to have a look at all the transits over a two day period.

Do you have a favourite ISS image you’ve taken?

Out of the 70 some shots I've taken of the ISS, my favourite has to be the ISS and Endeavor a few hours after undocking. That was the last visible pass of any shuttle over Kentucky. It was absolutely spectacular watching them streak across the sky and something I'm never going to forget.

How did using Triggertrap change your workflow for capturing ISS transit images?

Trying to take a photo of something 300 miles away moving at 17,500 mph that you can't see, pass in front of something you can't look at is difficult to say the least. Especially when at best it lasts for 1.3 seconds and at worst 0.5 seconds. Timing is absolutely everything. I press the shutter a half second late, I miss the shot. What the Triggertrap allows me to do is eliminate my number one point of failure, human error. Since I started using Triggertrap to activate the shutter, I've increased my success rate from 60% to 100%.

What are your top tips for someone trying this technique for the first time?

You must have patience, perseverance, and attention to detail. I've lost track of how many times I have packed all my gear, driven to some distant place only to have clouds roll in at the last moment. Get as close to the centreline as possible, otherwise the ISS will be off-centre of the disc of the moon or sun. Finally, double-check all your data before you leave the house. I've seen a pass shift by a mile in the last 24 hours.

What will you be working on next?

I've been researching weather balloon photography for a while. Maybe telling the world will help motivate me to finally do it.

Want to see more from Aaron?

Take a look here to find out exactly how Aaron captures his ISS photographs. You can check out more of Aaron's astrophotography over on his Flickr page, and Instagram. For more of his tips and tricks head over to his blog. For ISS predictions specific to Bowling Green, Kentucky take a look here

We want to see your photos!

Have you tried your hand at some astrophotography lately? We want to see your photos over on our on our Flickr pool. Get in touch by tagging us #Triggertrap and @Triggertrap on TwitterInstagram, and Facebook.

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