Shooting with a tracker
As it was my birthday month, I order myself an extra special birthday gift- the iOptron SkyGuider Pro. For those not in the know, a star tracker is a mount that attaches a camera to a tripod. What is so special about this device is it compensates the earth’s rotation, moving with the stars so that you are able to take really long exposures without getting star trailing. I was stoked to finally get one! As here in the UK (at quite a high latitude) the Milky Way core isn’t really visible over summer (and it doesn’t get dark enough), I decided to book a week off work so I could get out every night- clouds willing!
FThere are lot’s of different star trackers out there, and after reading lots of reviews and asking for advice on astro groups I am on I opted for the iOptron SkyGuider Pro. If you are looking to purchase a tracker, I got mine from First Light Optics. The service was excellent, and replies to my emails with queries was excellent.
My tracker arrived, and I excitedly unwrapped it. I practiced assembling it at home, and watched a tonne of videos on polar aligning (more on that shortly) and setting up, and asked for advice and tips on groups that I am on. I felt ready for my week of astro!
All in all I managed to get out three nights to shoot with clear skies. The first was the incredible dark skies of Elan Valley. I encountered lots of roadworks en route and arrived later than expected. I hurriedly set up- and the cloud rolled in to where the Milky Way would be. I sighed with frustration. Not to worry, the sky was clear to the North I could practice polar aligning. In order to get crisp sharp stars with no trailing, you need to point the tracker at one of the celestial poles. In the UK that is the North celestial pole, and handily we have a star caller Polaris. You point your tracker due north, adjust the tracker to the right latitude (there is a handy app that tells you what latitude for where you are), look through the scope, see Polaris and use gently adjust the tracker until Polaris is in the correct spot that the app shows you. Sounds easy, right?!
One problem- which star is Polaris? There were SOOOO many stars North, and North is not a direction I have spent much time looking at admittedly. Heck, this was going to be harder than I expected. After much faffing around, I decided pointing North would have to be enough. The clouds cleared a little and I took some 30-60 second exposure shots of the Milky Way. I usually shoot 15 max without a tracker. The stars looked fairly sharp, and as time dwindled I decided my next outing I would arrive much earlier to spend time polar aligning.
My second location was a road in Snowdonia with a keepers cottage- I assumed this was abandoned but it turns out it is actually a holiday cottage and someone was staying there! I moved further down the road. I still wasn’t convinced I had polar alligned properly, but was able to get some better shots. The above image is a composition from that night.
The next evening I spent some time looking at Stellarium at Polaris, so I knew where Polaris would be and how to find it. I went to Aberdaron beach, got there early and spent a LOT of time on my knees in the wet sand gazing through the polar scope. I was more confident than last time, but still not 100%. I managed to get some wicked shots, 3-4 minute exposures. The sky was amazing! The car park here is also open all night, and there is a toilet that was open all night if you fancy going there to star gaze.
All in all it was a steep learning curve, but it was great to see the improvements over three nights. Editing is also a bit different as you may have sharp stars BUT you get a blurry foreground so you need to turn the tracker off to take a foreground shot and blend the images in post production. Next step- order a laser for polar aligning!