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Review: A New Travel Mount for Astrophotography

We put the LighTrack II from Fornax Mounts through its paces.

Eta Carinae Nebula imaged by Gary Seronik

One of the treasures of the southern sky is the magnificent Eta Carinae Nebula, shown in this image captured with a Nikon D5100 camera and 135mm lens on the LighTrack II mount. Courtesy Gary Seronik

Two persistent trends in night-sky photography have intersected in the past few years. Trend #1: Digital cameras have been getting better and better when it comes to low-light performance—and no application is more “low light” than astrophotography. Trend #2: Fans of dark night skies travel farther and farther afield to escape big-city light pollution. So it’s little surprise that a new crop of highly portable tracking mounts designed specifically for DSLR astrophotography has appeared.

A tracking mount is really a one-trick pony—and that trick is to compensate for the Earth’s rotation. It accomplishes this by moving your camera in the opposite direction at precisely the same rate—one revolution per day. The tracking motion ensures that stars in long-exposure photographs appear as tidy points of light instead of the long streaks you get with a camera attached to a stationary tripod. But for a mount to perform well, it has to move both smoothly and accurately.

The LighTrack II from Fornax Mounts claims a minuscule periodic error of only two arc seconds over an 8-minute span. Given that most photographers will use the mount for exposures of 5 minutes or less and with lenses of focal lengths shorter than 300 millimetres (the maximum recommended by the manufacturer), that’s plenty accurate.

Features and Details

The LighTrack II is the heart of a highly portable setup that is ideal for the travelling astrophotographer. The camera, ball head and tripod are supplied by the user, while the polar-alignment scope and FMW-200 wedge are options that can be purchased with the tracking mount.

The LighTrack is a well-made, sturdy piece of equipment consisting largely of anodized aluminum components. You can purchase the tracker alone or with an EQ5 polar scope or in a “full set,” with both the scope and the FMW-200 adjustable wedge (the option we tested). The FMW-200 can also be purchased separately. The user supplies the camera, ball head and heavy-duty photographic tripod.

Together, the scope and wedge make accurate polar alignment much easier—something that’s critical for perfectly round star images, especially with long-focal-length lenses. The polar finderscope worked well, but I did find myself wishing it had come with an illuminated reticule. Under a dark sky, the reticule markings necessary for sighting the celestial pole are nearly impossible to see. Shining a flashlight into the scope proved an awkward compromise at best.

Precisely adjusting the aim of the LighTrack is facilitated with the fine motion controls of the FMW-200 wedge. This beautifully machined item worked very well, though sometimes the mount’s position would slip a bit when I turned the knobs used to lock the altitude adjustment. Affixing the mount to the wedge is a bit fiddly, but it’s a onetime only operation best done beforehand in daylight. The scope and wedge are worthwhile additions unless you exclusively use wide-angle lenses. I recommend both items. All together, the mount, finderscope and wedge tip the scales at just a hair over 2.5 kilograms (5.5 lb).

Capturing Photons

To begin a night of astrophotography with the LighTrack, you attach the mount and wedge assembly to your tripod. For maximum rigidity, it’s best to use the tripod’s centre post and avoid the pan/tilt head, if possible. The thread on the base of the wedge is 3⁄8-16, so if your tripod is 1⁄4-20 only, you’ll need to pick up an adapter bushing.

FMW-200 wedge

The optional FMW-200 wedge has fine-motion controls in altitude and azimuth to facilitate precise polar alignment, which is crucial for perfectly round star images.

Controls

Only a few controls are needed to operate the LighTrack. You can choose from four different tracking rates for locations on either side of the equator.

Of course, if you’ve opted to purchase just the LighTrack alone, you’ll have to align on the celestial pole by using the tripod’s adjustable head. Next, plug in the 12-volt power cord. It comes with an automotive-accessory (cigarette-lighter) fitting so that you can power the mount from your vehicle or from a portable battery pack. Finally, affix the ball head to the mount (again, with a 3⁄8-16 socket), and attach your camera. After carefully polar aligning, you’re set to take pictures.

The LighTrack’s control panel is attractively spartan and intuitively laid out, consisting of four buttons and seven LEDs. The leftmost button allows you to toggle between several tracking rates, including sidereal (for imaging stars and deep-sky objects), solar and lunar. In addition, there’s a “half” speed for capturing wide-angle night-landscape photos with minimal blurring of the foreground and star field. Next is a button for selecting which side of the equator you’re on (north or south), and at the far right of the control panel, there is a pair of buttons to rapidly move the mount forward or backward. These are used to reset the mount once it’s reached the end of its travel.

LighTrack

The LighTrack compensates for the Earth’s rotation by moving the camera in the direction indicated by the arrow.

Powering up the unit by means of a switch on the rear of the control panel initiates a discreet, audible trill—like a vaguely musical frequency sweep—and lights a pair of small red LEDs, all to indicate that the mount is tracking. Conveniently, the LighTrack defaults to a sidereal tracking rate and the northern hemisphere when activated.

In use, the LighTrack is vibration-free and dead-quiet (except for the aforementioned musical trill). It provides roughly two hours of continuous tracking (our test unit clocked in at 1 hour 50 minutes), but the manufacturer notes that for best results with long-focal length lenses, exposures should be kept to 6 minutes or less and should utilize the middle portion of the mount’s tracking range.

Quirks and Quibbles

In my many weeks with the LighTrack, I found little to complain about. The mount tracks the sky very accurately, and really, that’s all it’s designed to do. But it’s worth keeping in mind that a good mount alone doesn’t guarantee perfect pictures. Trailed stars can be the result of imprecise polar alignment, flexure in your tripod or ball head or even a tripod leg slowly sinking into soft ground. (That last one is from personal experience.) The longer the focal length of your lens, the more obvious these pitfalls become. And yet when everything works, the results can be truly rewarding—something I experienced often with the LighTrack.

In the end, I have only a few quibbles. First, the mount doesn’t warn you when it’s reaching the end of its travel—it simply stops dead in its tracks. It’s not a terrible burden to remember to reset the mount after shooting a few image sequences, but some kind of signal would be nice when the mount is down to its last 10 minutes of tracking.

Another quibble is the user’s manual. To put it kindly, it’s minimal. True, the mount is pretty simple to use, but a single folded sheet seems a poor match for such a premium piece of gear. And there are a couple of omissions. Nowhere does the documentation mention the auto-guider port or the function of the status light on the control panel. While a modestly experienced astrophotographer will be fine with the existing documentation, a beginner might yearn for more details.

Milky Way panorama

This sweeping panorama captures the rich swath of Milky Way extending from the Southern Cross and the Coal Sack dark nebula (right) to Alpha and Beta Centauri  The scene consists of a pair of images digitally stitched together. Each 2-minute exposure was shot on the LighTrack II mount with a Nikon 50mm lens and Nikon D5100 DSLR camera
at ISO 800 and f/4. Courtesy Gary Seronik

Finally (and this is the elephant in the room), there’s the matter of price. There is no getting around the fact that the LighTrack (especially the version we tested) represents a significant outlay. There are several less expensive options available, including the iOptron SkyGuider we reviewed previously. Is the LighTrack’s topflight construction and exceptional accuracy worth the extra money? That’s largely a personal decision, but if you need superb portability and plan to regularly use lenses in the 100-to-300mm range, the LighTrack II deserves a place near the top of your short list.

Gary Seronik is the editor of SkyNews. He has built several tracking mounts for astrophotography.

An expanded version of this review appeared in the September/October 2016 issue of SkyNews.

 

Categories: Equipment Reviews, Sky Photography
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