Any new telescope mount from Sky-Watcher always piques the interest of the amateur astronomy community, and we were eager to find out what features the new EQ-AL55i Pro, equipped with Wi-Fi connectivity, had to offer.
We got the chance to put it through its paces, testing alignment, GoTo, Wi-Fi control and astrophotography.
Read our guide to telescope mounts
Unboxing
When the package arrived, it was obvious that this is no grab-and-go travel mount.
The tripod is a full-size, steel affair.
The mount head itself, while not overly heavy, is solidly constructed and a decent size.
When you add in the counterweight bar and weights, the assembly is almost 15kg, without a telescope added.
Our package included the optional, and useful, 200mm tripod extension.
Global appeal
A key feature of the EQ-AL55i Pro is it can be used anywhere on the globe, thanks to a latitude setting that adjusts between 0° and 90°.
This is achieved with alternative counterweight bar placements.
For those observing with the North Celestial Pole high overhead, it will be necessary to remove the polar scope and the covering cap to adjust the mount into position.
The tripod extension is then required to ensure the weights stay clear of the front tripod leg when the mount is set to 0°.
The adjustment is quite coarse, but with practice we could make fine adjustments for polar alignment.
Powering up
With the mount set up and powered via our 12V DC supply and roughly polar aligned using the in-built polar scope, we attached our 75mm refractor with an eyepiece.
The mount will handle a payload up to 10kg if desired; an additional 5kg counterweight is available to purchase if needed.
We only needed the heavier of the two provided weights to balance our equipment, so there was no real strain on the DC servo motors.
They are not overly noisy in use, but you can certainly hear them when slewing at higher speed settings.
There’s a different tone to the right ascension (RA) against the declination (dec.) motor, which is expected considering the different gearing for each.
The larger RA worm gear has 144 teeth for accuracy, while the more functional dec. worm has 100 teeth.
Aligning and pointing
We expected the Sky-Watcher mount to be very accurate as far as Go-To capability is concerned,
and we weren’t disappointed.
After performing a three-point alignment, the EQ-AL55i Pro niftily put subsequent targets in the field of our 13mm eyepiece, no matter where in the sky we chose – the Pleiades, the Crab Nebula and the Whirlpool Galaxy, then on to Bode’s and the Cigar Galaxy.
Suitably impressed, we slewed to Regulus, centred it, and went inside for a warm drink to see how the mount would track a relatively fast-moving target over time.
Over an hour later, it was reassuring to see that Leo’s eminent star was still dead centre in the eyepiece.
With that settled, it was time to try some astrophotography.
Astrophotography with the Sky-Watcher EQ-AL55i Pro Wi-Fi mount
With our camera and guide camera attached, we carried out the polar alignment routine in PHD2, calibrated the guiding and started a run of five-minute exposures using the Leo Triplet and Orion Nebula as target choices.
We found it worthwhile to spend some time fine-tuning the guiding settings in PHD2, particularly for backlash compensation.
As the PHD2 graph demonstrates (see above), the mount responded well to the guide commands,
and with a bit of practice we had the ideal settings dialled in.
Thus we were able to take a series of 10-minute exposures that produced tight, round star images – an impressive result for the EQ-AL55i, especially on a target so far from the celestial pole.
Indeed, it seemed positively keen to perform, making it an appealing unit to take off to a dark-sky site and get on with the business of guided deep-sky astrophotography, with minimal fuss.
With Wi-Fi connectivity, an easy set-up and accurate Go-To and guiding, the Sky-Watcher EQ-AL55i Pro offers an attractively priced and versatile mount, suitable for global astrophotography or general observing.
Wi-Fi and Synscan app
While a regular Sky-Watcher handset can be purchased and plugged in, the beauty of the Sky-Watcher EQ-AL55i Pro is the freedom of Wi-Fi connectivity.
The mount sets up its own Wi-Fi with a range of a good few metres, which we connected to via the SynScan Pro app (free for Android, iOS or PC).
This makes perfect sense, as we could control it via a familiar device we already had at hand.
The app is perfect for visual observing, offering a large library of objects, while connecting via PC gives the option of wire-free connection and control, including the ASCOM connection for auto-guiding.
The process of linking to the mount is effortless, and the connection proved to be stable and reliable.
Intriguingly, although it isn’t mentioned anywhere in the manual, or indeed on the official descriptions at the time of reviewing, we noted a Bluetooth logo on the unit, along with the Wi-Fi one.
A quick check showed that we could also connect to and control the mount via Bluetooth using our phone.
Sky-Watcher EQ-AL55i Pro Wi-Fi mount 5 best features
Illuminated polar scope
Tucked within the mount body is a polar scope with an etched reticule, displaying the position required for Polaris or Sigma Octantis. You just pop the caps off either side to use it for polar alignment. The scope is illuminated and the brightness can be controlled or turned off via the SynScan app.
Counterweights
The two counterweights provide for a wide range of equipment, the chunkier one weighing 3.5kg. The slimline unit is just 1.8kg and allows balance to be more easily fine-tuned when using lightweight gear. An optional extra 5kg weight is available if required to counteract heavier telescopes (up to 10kg).
Tripod
The standard Sky-Watcher steel tripod weighs in at 5.7kg. It is adjustable to place the mount head between 87cm and 120cm from the ground. The spreader plate locks it into position and provides a tray for 2-inch and 1.25-inch eyepieces. The legs are tipped with rubber points to lessen vibrations.
Dovetail and clutches
Telescopes and cameras are attached to the mount via the 45mm Vixen-style dovetail saddle. This has a single threaded locking bolt with knurled handle. The declination locking clutch is opposite this, while the right ascension axis is locked in place by a larger wheel that is comfortable to use.
Ports and connections
The mount has a standard ST4 port for autoguiding and a SynScan handset port. The opposite side has a modern USB-C socket, making clunky serial port connections a thing of the past. In addition, a SNAP socket is provided for DSLR trigger control via the SynScan Pro app.
Vital stats
- Price: £779
- Mount type: Equatorial with Go-To
- Load capacity: 10kg
- Slew speed: Up to 4° per second
- Power input: 12V DC
- Autoguider port: ST4
- Protocols: SynScan, ASCOM via Wi-Fi or USB
- Weight: 14.8kg
- Supplier: Optical Vision Ltd
- Email: info@opticalvision.co.uk
- www.opticalvision.co.uk
This review appeared in the June 2024 issue of BBC Sky at Night Magazine
