The Altair 60 EDF doublet refractor is a lightweight tube assembly that weighs 1.5kg and almost fits in the palm of your hand. It’s ideal for a multitude of purposes, including as a travel scope and for wide-field imaging.
It is suppled as an optical tube only, giving you the flexibility to use your own star diagonal and eyepieces for visual observations, as we did for the review. Also in the box is an extendable dew shield.
The telescope tube has a hinged mounting ring with a foot for attaching to a tripod, and the focuser has 75mm of travel and a tensioning screw to prevent heavy accessories from slipping.
It also sports a camera angle adjuster, which allows you to rotate your camera without the need to rotate either the telescope tube or the focuser.
For our review, we used the 60 EDF as a simple visual wide-field scope attached to a standard photographic tripod, on a Sky-Watcher Star Adventurer tracking mount for astrophotography with a DSLR, and on an NEQ6 mount for imaging with an Altair GPCAM2 290C CMOS camera for close-up imaging.
For our visual tests, we added a dielectric star diagonal and a range of eyepieces. Using a 2-inch 26mm eyepiece we examined the field of view using Deneb in Cygnus as our test star.
The view was pin sharp across 85 per cent of the view, with only slight distortion at the edges and little sign of colour fringing, showing that the lens design was doing its job.
We then took a tour around the best targets in the sky at the time, our first port of call being Orion, where we discovered that we could fit the three stars of Orion’s Belt and most of Orion’s Sword into the same field of view, and enjoyed the wisps of nebulosity of the Orion Nebula.
Swapping to a 2-inch 9mm eyepiece gave enjoyable views of the nebula, with the stars of the Trapezium Cluster glittering at the centre.
We also used the 2-inch 26mm eyepiece on the Pleiades and the Andromeda Galaxy, tracing out the latter’s disc for several degrees.
Naturally some targets required 9mm or 10mm eyepieces to give a bit of extra magnification, and with these we took in the galaxy pair M81 and M82, the wide double star Mizar and Alcor, and the Beehive Cluster in Cancer – which was particularly good in our 100° wide-field 9mm eyepiece.
With the 2-inch 26mm eyepiece (with a 70° field of view), we were able to see plenty of the Milky Way surrounding the Double Cluster in Perseus – indeed, this combination was ideal for scanning star fields.
We then attached the 60 EDF to a Sky-Watcher Star Adventurer portable tracking mount and added a Canon EOS 50D DSLR, happily taking two-minute, wide-field exposures of the Pleiades and the Andromeda Galaxy with pleasing results.
The 60 EDF is particularly suited to such tracking mounts, making it great for taking away on holiday to capture deep-sky vistas abroad.
The mounting foot on the 60 EDF is ideal for such a mount of this size; should you wish to attach the scope to a larger mount, you’ll need a 200mm Vixen bar.
When we used our own Vixen bar to attach the 60 EDF to a NEQ6 mount it did feel like overkill, yet by doing so we could take a variety of long exposures with our GPCAM2 290C colour camera and capture wonderful detail in the Orion Nebula.
We found that we were able to frame the nebula easily by using the camera angle adjuster.
If you are looking for a capable telescope that can cover wide-field visual observing through to imaging, and is straightforward in use throughout, then the 60 EDF certainly does the job.
Grab and go for all occasions
If a telescope is large and heavy, then there is a good chance it may not get used that much, but small, short focal length scopes such as the 60 EDF come into their own by being incredibly portable and versatile.
Weighing 1.5kg and only 23cm long, it easily fits into luggage – making it a great scope to take to a dark site or on holiday without feeling like you are carrying an observatory around with you.
The 60 EDF can be attached to a simple tripod for basic wide-field observing with a star diagonal and eyepieces, or attached to a tracking mount for a simple and quick astrophotography setup that you can take anywhere.
Add in an erecting diagonal and you even have a spotting scope for nature and wildlife use during the daytime.
The front lens element consists of a synthetic fluorite S-FPL53-based doublet objective lens with multicoatings on all optical surfaces for good control of colour correction and the lens is slightly oversized to provide better edge quality.
The dew shield was very smooth in operation. It is retractable, and only adds 7cm to the scope’s length when extended. It worked well under moderately damp conditions, allowing us to spend an hour imaging before the lens began to dew up.
Camera angle adjuster
Your celestial targets will not all be orientated the same way in the night sky. The camera angle adjuster allows an attached camera to be rotated, yet held firmly in place, without affecting focus or having to rotate either the focuser or tube.
Hinged mounting ring
This is a very light telescope, so it doesn’t require normal tube rings. Instead it relies on a hinged single tube ring and tripod foot. The tube ring can be loosened to help rotate the tube and the foot has three M6/¼-inch in-line holes for attaching to a tripod.
The 2.5-inch rack and pinion focuser has 75mm of travel and offers dual-speed 1:10 fine focusing. There’s also a tension adjustment screw, and this allows for heavy equipment such as large cameras to be attached and locked, so the focus doesn’t slip during imaging.
This review originally appeared in the February 2018 issue of BBC Sky at Night Magazine