Sky Watcher Star Adventurer Tracker
How to set up
I’m going to assume that you have the full pack, which includes the tracking unit itself, the EQ wedge, counterweight and bar, declination plate, ballhead mount adapter, and the polar scope illuminator. Ignore my own counterweight in the above image, that’s just me. But if you want to order one similar, then let me know and I’ll add into the links. This walkthrough has now been updated to include guiding with the Star Adventurer.
As with any astrophotography platform, the first thing you need is a stable platform. By this I mean the tripod itself. One of the cool things about the Star Adventurer is it’s portability and you don’t really want to be adding too much in the way of things that start inhibiting that. However, that said, if you have an unstable platform, then it’s going to affect your ability to image successfully. There’s a dedicated tripod for the Star Adventurer already, and although this is perfectly adequate, because my own setup with it is quite weighty, I opted to upgrade the legs on mine and go with something that is a lot sturdier and could give me room to upgrade the mount without having to upgrade the tripod as well. So I opted for a 3/8″ stainless steel one. Yes, for the Star Adventurer it’s complete overkill and it has more weight to it. But it’s solid and if you’re like a large proportion of us you’ll probably want to throw a small refractor telescope on there at some point. If you’re going to do this, then I definitely recommend the SkyWatcher 72ED as it’s small and, even with a DSLR mounted to the scope, within weight and balance limits…just. If you’re going to go that route, then I can also recommend getting yourself a longer dovetail at the same time, specifically the 33.5cm one from the link. The reason for this is balance. I cannot stress how important balance is once you start down this road, and the longer your focal length, the more essential it becomes. You CAN balance with the stock dovetail, but there’s not a lot of room to manoeuver, and even less if you’re going to start adding things such as focal reducers etc. So, for your sanity, go with the longer dovetail. And PLEASE, for the love of all that’s holy, don’t attach a ballhead to this. Trust me, unless you’re shooting small and light in widefield, it’ll cause more issues than it’s worth. Thank me later 😉
When initially setting up for an imaging session, there are four things to immediately do; level, balance, focus, polar align. If you don’t do these things well then your images will suffer for it. You won’t be able to expose for longer frames, which lets face it, is probably one of the primary reasons you bought the kit in the first place, your stars will start trailing, they’ll be out of focus, and you’ll also put a lot of stress on the equipment. So let’s take each of those things in turn.
Why do we need it to be level? No, it’s not because everything will look at a funny angle when you image it. It’s space, there’s no up, down, left or right. We level it because if we don’t then it inhibits the tracker’s ability to keep itself aligned with celestial north, which in turn will affect your ability to take longer exposures. So we level it as near as perfect as we can. For this the EQ wedge that comes with the Star Adventurer has a spirit bubble fitted into it. It’s not the greatest in the world, but it does the job. If you want to be really pedantic about it, and this is purely down to personal preference, you can get an actual spirit level and place it across the top surface of the tripod prior to fitting the Star Adventurer to it, and check acoss two or three directions if it’s perfectly level. Because I’m not a huge fan of taking the equipment apart constantly, I go with the bubble level method. For me its quick and it’s accurate enough.
You can see from the image that I’m not 100% level and am ever so slightly out a little. But I find it to be accurate enough for my purposes.
There are two axis in which you need to be balanced; RA (or right ascension) and DEC (declination.) These are the two axis that an equatorial mount moves around, and if you’re not as well balanced as possible then, again, you won’t be able to take longer exposures without introducing trailing into your images. What you’ll also do is put more strain on the gears and run the risk of them becoming unusable sooner.
DEC balance – this is the axis the OTA (optical tube assembly, or telescope itself) sits along. You balance this by finding the centrepoint with all the equipment added (camera, reducer etc.) This is why the longer dovetail is more useful as you can slide the entire assembly along it and achieve better balance when you have more kit such as focal reducers etc.
RA balance – check this by undoing the black clutch ring so that you can move it freely. From there, adjust the position of the counterweight along the shaft. You may find even with the counterweight all the way to the bottom of the shaft that you’re unable to achieve balance. There’s three ways to approach this; reduce the amount of equipment you have mounted, add a counterweight extension bar, or add a second counterweight. I went with the latter on my setup and managed to achieve perfect balance. This was with the ED72, a Canon 450D (plus adapter to fit to the focuser), 9×50 guidescope and ZWO ASI120mm guidecam, plus all associated cabling.
I would at least hope that this is pretty self explanatory. You can’t take an image of anything if you’re not in focus. There’s a couple of ways to achieve this and I’m going to go through the ones that I use.
First off, go to a bright star. You can use the “Live View” function on your DSLR. This applies if you’re using it with either one of it’s own lenses or it’s sat at the focuser end of the the OTA. Switch to Live View and then, using the Zoom control (NOT by zooming in by twisting the lens itself if you’re just using the DSLR and an associated lens) to get to x10 zoom. Then, either by using the focus ring on the lens to get to around infinity focus, or by using the focuser on the telescope, twist and turn until you have pinpoint stars.
Something that is absoutely essential in aiding focusing is using something called a Bahtinov Mask. This will get you to perfect focus. They come in all sizes and there will be one that’s suiable to your own setup, and are the easiest way to achieve pinpoint focus. Place the mask over the objective end (that’s the end that actually points at the sky) and then look at the image. What you should see is a large “X” with a line going through it with the star at the centre of the “X.” Adjust your focus until all lines intersect perfectly and are in alignment with one another. You now have pinpoint focus.
You can also use the focus tools within such software as APT, NINA, SharpCap etc both with and without a Bahtinov Mask. I use a motorised focus system with the mask and as such can control the focus from the laptop via APT. Just make sure you take the mask off once you’ve achieved focus. We’ve all done this, so don’t feel too bad if you forget to do it. At worst you’ll only lose a couple of frames if you do forget.
I also run my focus routine at the same time that I do my polar alignment, which I cover in the next section. Be aware that you’ll likely lose some light transmission with a mask on, so adjust your exposure times accordingly. The great thing about using a Bahtinov Mask is that it literally takes a few seconds to slip it on and it’s a good idea to check your focus hasn’t shifted throughout an imaging session.