Drew tries out the Sky-Watcher Star Adventurer, a star tracker for astrophotography
With technology ever advancing, it’s becoming even easier and more accessible to capture out-of-this-world images of the night sky. Having progressed from the age of heavy, large telescopes coupled on complicated tracking mounts, which were costly and took a day to setup, we’re now blessed with new portable, lightweight compact products that are packed with features. More importantly, the ability to bolt our cameras on them too!
There’s been an explosion of star tracking mounts for astrophotography in the last few years, all of which do a fantastic job of helping photographers capture exceptional images of the night sky. They all work on the old principle of what is effectively a “barn door” tracker – a rudimental way to capture long-exposure images of the sky without stars trailing, as the camera is rotating at the same speed as the earth revolves.
A simple single-arm barn door tracker can be made by attaching two pieces of wood together with a hinge. A camera is mounted on the top board, usually with a ball head to allow the camera to be pointed in any direction. The hinge is aligned with to our celestial pole, Polaris, and the boards are then driven apart (or together) at a constant rate, usually by turning a threaded rod or bolt.
However, these types of mounts are only accurate for short amounts of time before tracking errors become apparent. This is where the new motorized and custom built tracking mounts come into play. They are relatively quick to set up, and once aligned can track for up to five hours on just four AA batteries, doing so with (in my short experience) no alignment errors. Pretty impressive!
As I do a lot of astrophotography and also run night sky photography workshops here in Pembrokeshire, Wex were kind enough to send me the superbly named “Sky Watcher – Star Adventurer”, asking me to put it through its paces and to see what could be achieved from this little mount.
First impressions out of the box are that it’s a nicely made piece of equipment! Extremely compact on the whole, quite sturdy, and there’s a very smooth motion to the bolts and screws, which helps to tweak any adjustments to the alignment. It comes with plenty of accessories too!
Quick setup guide for shooting in the UK
To start photographing the night sky, you’ll need to set up the mount in a certain order. This way, once it’s running you can point your camera in any direction and the tracking mount will remain accurate. Any tiny errors in this setup stage will show themselves in your images, so this is the most important part! It’s always good practice to give this a trial run in the daytime to familiarise yourself with the process and also the equipment.
Whether you use the tracker in your garden or take it to a new location, remember to get the best long-exposure night sky images you need to head away from the city lights to a dark-sky location. You’ll also need four AA batteries installed into the tracker for it to work.
First up is your tripod – the bulkier the better, as stability is the key with long exposures. Also you don’t need to extend it to the full height as this will weaken it. A mid-height setup works best, retaining strength while meaning you don’t have to sit on the floor. You also want the level the tripod as best you can.
Next up is the Equatorial Wedge. This will screw onto the top of your tripod in place of the three-way pan/tilt head. It’s more accurate than a standard head during the alignment process. There’s a spirit bubble on this so here’s the time to make any adjustments to your tripod legs, and achieving a level bubble.
Also, you want to roughly point the Equatorial Wedge north. The quick way to do this is twist the Latitude Adjustment knob until the indicator points to zero, then you can place a compass on the mounting plate and rotate the tripod until you’re pointing north.
The included quick release plate needs to be attached to the bottom of the Star Adventurer. Make sure the screw is tightened and the stopper is in the recess, then slide the Star Adventurer into place on the Equatorial Wedge and tighten up.
Next up is the polar alignment. Remove the Polarscope eyepiece cover. Undo the large clutch knob and rotate the wedge for the Date Graduation circle to align October 31 to the 0 of the Time Graduation Circle, then tighten the clutch knob again.
This way, the display in the polar scope will be upright, which is vital for polar alignment. Remove the Polarscope cap to install the Polar Scope Illuminator, turning it on to make the red light increase.
For this you can use a phone app called Polar Scope Align or PS Align.
Using this app while on your phone will help you with two things. It will give you your GPS co-ordinates so you know what latitude to dial in on the Equatorial Wedge. The app will also display where Polaris needs to be positioned in the Polarscope display. Mine was around 51 degrees, so I rotated the Latitude Adjustment knob to match, using the sideways adjustment knobs too if needed.
This is for Northern Hemisphere users. Finding Polaris is relatively easy – first you must find the Plough (Ursa Major) and follow the vertical stars that make up the end of the pan upwards. This is Polaris, the closest main star to our celestial pole.
Once you’ve aligned Polaris’ position to match that on the app, turn the Mode Dial to Celestial tracking (with the star symbol). This will start the tracking motors.
The next step depends on what you’re using to photograph and determines what mount you use. If you’re shooting wide angles with relatively little camera weight, then just use the Ball Head Adapter slotted into the top of the Star Adventurer to screw your ball head and camera in place. If using a longer lens, heavier camera or even a telescope, then use the fine-tuning mounting assembly together with a counterweight attached to slot into the Star Adventurer.
Try to do all this without knocking or changing the alignment of the mount, which is tricky but it will save you having to take it all off and realign. Now everything’s attached and the motor is running on the correct mode, you’re all set for a night of astro photography. Below is a quick visual reference for how the mounting process should look:
Here’s one result from a night shoot trying to capture the Orion Nebula (M42)
It’s made up of 32 images, each image being a 60-second exposure taken on a Canon EOS 5D Mark III with a 300mm f/2.8L IS USM lens attached. It’s by no means perfect, and I’ll talk more on the how to process deep-sky images in part two to this review, as well as going through the other functions of the tracker. However, I must say that my first impressions are that I’m very impressed with this Star Adventurer!
The name of the game with deep-space images is that the longer you can expose for, allowing light to flood into the camera, the more information (stars/nebula) you will capture. Having something that tracks with the stars to facilitate this, and is also small and portable, makes me realise what a very powerful piece of equipment it is. A superb addition to have in the kit bag and something I could easily carry for a few miles into the wilderness. I can’t wait to get to grips with the Star Adventurer and produce more images as we head towards the summer and the Milky Way becomes more prominent and magical.
About the Author
Drew Buckley is a multi-award winning landscape and wildlife photographer based in Pembrokeshire, Wales. He's authored many books and runs his own photography workshops in Pembrokeshire and on Skomer Island in the summer months. Check out the availability calendar on his website to book a workshop. Visit his website, find him on Facebook, and follow him on Twitter.