The first equipment I built when I was young in the hobby of astronomy and photography was a portable tracking mount. My homebuilt versions caused me no end of frustration trying to track down the reasons for trailed images, and of course the month turn-around on a roll of film meant the feedback-improvement loop was very slow. Twenty years later we're now spoilt for choice with a number of very compact and capable tracking mounts on the market.
My early experience with tracking platforms
These portable tracking mounts are intended primarily for use with DSLRs and wide to moderate focal length lenses. Notable examples include the Vixen Polarie and iOptron SkyTracker, both of which I have used, and somewhat more recently the Skywatcher Star Adventurer. Skywatcher's contribution to the field is a larger but ostensibly sturdier tracking mount, with an additional focus on timelapse motion control as well as tracking.
Southern Cross with Canon 6D and 80mm lens
Tracking on Skywatcher Star Adventurer
80 * 30 secs, f2.8, ISO3200
In the Box
While you can buy the Star Adventurer unit on its own, most people would go for the bundle which includes all the components in the image below. As a guide, this is available for AUD $599 from BinTel in Australia.
Star Adventurer Bundle
The latitude adjuster provides a solid base for the Star Adventurer and has effective fine adjustments for both the altitude and azimuth of the polar axis. It also covers the full range from 0 to 90 degrees, which makes it quick and easy to switch to horizontal or vertical panning modes for timelapse. The Star Adventurer unit alone weighs 1.2kg plus another 0.5kg for the latitude base.
The easiest approach for mounting the camera is to use the included ballhead adapter, which slots into the Vixen style dovetail on the Star Adventurer. You'll need to provide your own solid ballhead. The locking screws engage positively into a recessed dimple on the dovetail bar. The large screw would be easy to operate with gloves and there's never any concern that the ballhead adapter could slide out even if it wasn't tightened up properly.
These are all definite positives compared to the other tracking mounts I've used. The image below is the configuration I used for most of the example images included with this post.
Star Adventurer with Ballhead and 200mm lens
The Star Adventurer also includes an Equatorial Head and Counterweight for a more balanced approach. The declinition head is not motorised but does include a fine adjustment knob for easy target centering even at longer focal lengths.
Star Adventurer with Equatorial Head
The polar scope illuminator appears to be something of an after-thought and is unfortunately not built-in to the unit. While it doesn't provide very even illumination it does the job much better than trying to shine torches down the tube and can be dimmed down to very low levels, unlike most illuminators.
The polar scope has the Octans asterism marked making southern hemisphere alignment straightforward if you know how to find that. My usual routine is to eyeball align the unit with south celestial pole by eye (it's well worth learning your way round that part of the sky). Then I'll use a digital inclinometer (or phone app) to set the altitude angle of the Star Adventurer. The cover on the batteries is square with the polar axis which makes that easy. At that point, the Octans asterism is usually within the field of view of the polar scope. In the Northern Hemisphere, you can go through the routine with the setting circles to set the orientation of Polaris or use a smartphone app (PolarFinder) for the purpose.
Then it's a simple case of selecting N or S and turning the dial to the Star symbol (Sidereal tracking rate). There are also Lunar and Solar tracking rates which would be very handy for lunar and solar eclipse photography with telephoto lenses.
The standard way to power the unit is with 4 AA batteries (it does takes a little bit of work to remove them from the compartment). Even with some old rechargeable batteries I was getting several nights use out of one set of batteries. With fresh batteries this would keep going for quite awhile or you plug in 5V via a mini USB connection.
I've found the periodic error on the Star Adventurer to be around 50" (arc-seconds). The image below was taken at a focal length of 400mm with the polar axis intentionally mis-aligned resulting in declination drift over the ten minute period of the worm. The same test with my iOptron SkyTracker shows a periodic error of around 100" while the Vixen Polarie was perhaps a little less at around 40". Your mileage with any of these mounts may vary! 400mm was way beyond the capability of any of these mounts but the Polarie felt the most precarious with such heavy loads.
Drift test revealing around 50" periodic error
These portable tracking mounts are really designed and suited to wide-field photography. With wide angle and standard lenses up to say 50mm you can achieve fairly long exposures, limited mostly by your polar alignment accuracy. One of the first images I took with the mount was this image of Comet 252P Linear at 35mm focal length.
Comet 252P Linear, 22nd March 2016
Canon 6D, Samyang 35mm lens f2.8, 2 mins, ISO800
The Star Adventurer is really well suited to this kind of opportunistic photo - the Full Moon was setting as astronomical twilight started, so it was hardly worth setting up larger amounts of gear. But it took only a few moments to setup the Star Adventurer and easily frame up this shot - this is what I call easy and fun astrophotography and it's highly motivating. All of these examples are shot with a standard (not modified) Canon 6D DSLR.
Once I moved up to 80mm focal length, I found I needed exposures of ~1 minute or less for pin-sharp stars and at 200mm I was using 30 second exposures. Two minute exposures at 200mm focal length were mostly trailed to varying degrees, but if you were just aiming for Facebook resolution then you'd still be fine. If you pixel peep and aim for perfection like I do then you'll need to stack lots of fairly short exposures for sharp images. But this 'track and stack' approach is well proven and is one I've used for a long time. The results below show what is easily achievable with this mount using my standard Canon 6D (click on the images to view them in high-resolution on SmugMug).
Eta Carinae region with Canon 6D and 200mm lens
300 * 30 secs (150 mins), f4, ISO1600
Orion with Canon 6D (not modified) and 200mm lens
80 * 30 secs (40 mins), f4, ISO1600
Mars and its rival Antares, Canon 6D and 200mm lens
65 * 30 secs (32 mins), f4, ISO1600
One somewhat surprising feature of the Star Adventurer is the ability to auto-guide the unit, via a standard autoguider port. Guiding is only in RA (right-ascension) as there is no motor on the DEC (declination) axis. I can't think of many situations where I would use this as the extra weight of a polar scope and guide camera would make for a pretty hefty combination. But for some people with a particular setup or imaging goal perhaps this feature will find some use.
It's a good sign that there has already been a firmware upgrade to improve the timelapse performance of this mount. The instruction manual refers to the original configuration, where in anything faster than sidereal rate, the unit would oscillate 60 degrees back and forth (to prevent cables snagging) but would start from the middle of that range so the first pan would be only 30 degrees left or right. This would have been quite restrictive for daytime timelapse pans. Logic has quickly prevailed and the firmware now moves 180 degrees before reversing direction, making it very quick and easy to setup a quick horizontal or vertical pan for day or night timelapse. At sidereal and 0.5x rate, the unit will keep moving in one direction indefinitely.
Here is a very quick and simple demo of using the Star Adventurer for timelapse. This starts with a long all-night horizontal pan, then a daytime pan at 6x tracking rate triggered via the mount itself every 4 secs, finishing with a vertical pan. Each of these clips were very quick and easy to setup. At the end of the daytime clip you can see the motion direction reverses at the end of 180 degree pan. This was shot at 80mm focal length which was probably a bit long for a 4 second frame rate. I'd typically use a shorter focal length or trigger the images more frequently.
Skywatcher Star Adventurer Demo from Phil Hart on Vimeo.
If your sole interest was timelapse motion control, there are other products on the market that provide a greater degree of programming control but the Star Adventurer is pretty capable for an affordable piece of kit and easy to set up. If you like the idea of being able to do timelapse as well as using this for tracking astrophotography then the Star Adventurer represents great value. Because the latitude base easily covers the full range from 0-90 degrees (for both horizontal and vertical pans) the Star Adventurer is much better suited to timelapse than the iOptron SkyTracker.
There's a helpful 2014 review from SkyNews available online if you want to read more on this mount. There's also a Yahoo Group to discuss future firmware improvements, apparently setup by Skywatcher.
Skywatcher were not the first to offer portable tracking mounts but the Star Adventurer unit is a very capable and complete package. It is heavier but also has a more substantial payload than the competing options and it did feel more comfortable supporting my full frame Canon camera and 200mm lens. Once you go beyond wide angle lenses, tracking accuracy still limits you to quite short exposures but a lot can be achieved with this portable 'track and stack' approach. The combination of flexible tracking rates, quality built-in polar scope and latitude base plus the suitability for timelapse should make this quite an attractive option.
In closing I'd note that I will be a photography guide for a solar eclipse tour in the U.S. in 2017 and if there's only one mount I can take with me, it will be the Star Adventurer.
Full Disclosure: Skywatcher Australia provided the Star Adventurer unit in exchange for this review. If you know how long it takes to prepare a review like this you'd probably agree they got a good deal ;-)