Altair Starwave 70 EDQ-R quad apo imaging refractor review
The Altair Starwave 70 EDQ-R is a four-lensed, lightweight scope designed for easy, wide-field astro imaging£1,150 Skip to view deals
Astrophotographers have an ever-growing wishlist of new kit as technology keeps advancing. The new Starwave 70 EDQ-R quad apo imaging refractor is another telescope to add to that list. The 70 EDQ-R has a 350mm, f/5 focal length and is aimed at wide-field imaging.
With the right camera attached it can fit some very large objects into its field of view. A quadruplet design of telescope is nothing new but some very careful attention to detail has made this telescope a lot more user friendly.
Quadruplet telescopes are made up of four lenses. The front three are for colour correction while a fourth lens at the back flattens the field of view.
The flattener being built in makes for a more stable imaging setup rather than having to insert a separate flattener in at the focuser end. The aim is to achieve round stars right into the far corners of your images and good colour correction across the entire image.
Where the quad differs from a normal refractor is that the rear end terminates in an M42 thread so that you can attach a camera directly to it, or, in the case of a DSLR, by using a T-adaptor.
With all telescopes, temperature changes can make a big difference to images. In a cold environment it is recommended that you heat the tube slightly.
This will help with the difference in glass and tube temperature and it can easily be achieved with a dew strap around the tube on a moderate setting.
Once we’d unpacked the 70 EDQ-R, the first thing we noticed about the telescope is how light it is: with a Canon EOS 70D DSLR camera attached it weighed just 2.1kg. This really does make it a grab-and-go telescope for even the smallest of mounts.
Even with a smaller aperture, the change in CMOS cameras over the last few years means images of all sorts of objects are achievable with this telescope.
That makes it an ideal travel scope and a good option to take with you on longer trips instead of a set of camera lenses.
Build quality in general is very good, and it comes with quite a lot as standard.
The tube is made from lightweight alloy with extending dew shield and it comes with a good set of adjustable tube rings on a dovetail bar. A quality rack and pinion focuser with nice, smooth movement adds to the quality feel. The only thing we did find that let it down was a loose lens cap that kept falling off.
While the 70 EDQ-R is primarily a telescope for astrophotography it can be used with an eyepiece by adding a 40mm extension to the back thread. For beginners this may make it easier to align finderscopes and mounts when first setting up.
The first target we imaged was the Andromeda Galaxy using a finder-guider configuration on a portable tracking mount set on a tripod. The camera was a Canon DSLR setup using the basic EOS capture on the computer.
We took 20 three-minute images which captured lots of detail in the dust lanes with round stars and vibrant colours. For such a short amount of imaging time we were happy with the end result.
The same process was repeated on a subsequent night with the Pleiades as our target, again revealing plenty of structural detail. Changing to CMOS cameras was simple and with M42-threaded extension rings on the camera it was easy to focus on the screen.
When you’re using a mono camera, there’s ample space to attach a small filter wheel in the imaging train if you need it. Images of the Moon with a Hypercam 183C showed a lot of detail for the aperture.
The 70 EDQ-R is a very good addition to anyone’s imaging setup and makes it very easy to capture good images with the minimal amount of effort.
Outstanding feature: Top of the glass
High-quality Japanese ED S-FPL53 glass is used for good colour correction. This, coupled with super-high transmission coating on all air-to-glass surfaces, ensures high contrast in images.
The four-lens system gives a flat-field image circle of around 42mm at 350mm focal length, with a focal ratio of f/5.
Having the correcting lens built in helps with the control of dust, while not having to attach correctors in front of the camera means less equipment to take out with you on imaging sessions.
When focused on infinity, the camera sensor is automatically at optimum spacing.
Using two ED elements in the optical arrangement gives minimal vignetting, which only starts to show in the corners of a full-frame 35mm fields The roundness of the stars remained well-defined right into the corners of the image too.
When coupled with a larger format camera or DSLR the 70mm design allows for excellent wide-field images. Wide-field views of the Whirlpool Galaxy, the Andromeda Galaxy and the Pleiades gave pleasing detail in our tests.
Lightweight aluminium tube rings and a Vixen dovetail bar are included. The dovetail bar has an elongated slot at one end for easy adjustment of the rings. This makes balancing the position of the telescope easy on any motorised mount. The bar has a thread to mount on a tripod and ball mounts.
Having a finder shoe is a nice touch as they’re often not included on smaller refractors. Based around a Sky-Watcher finderscope, the shoe is quite generous in size and doesn’t interfere with the rotation of the camera. It can also be used to mount a small guidescope or camera.
M42 rear adaptor
The M42-threaded rear adaptor is fully rotatable and makes framing targets really easy. All locking pins are nylon coated for secure locking. On the inside of the flange are adjusters to allow for sensor tilt. With the tilt adjuster set to zero the back focus is 66.78mm.
A high-quality rack and pinion focuser with a micro focuser for fine adjustment makes focusing easy. It can be fully rotated allowing the telescope to be mounted on a range of equipment without the focus knobs getting in the way. The focuser can support even the heaviest of cameras with nice smooth adjustment.
A sturdy built-in, fully retractable dew shield helps keep dew down to a minimum in average temperatures.It is coated black on the inside to stop any stray light entering the telescope.The dew shield has adjustment screws to make a firm fit to the tube.
- Price: £1150.00
- Aperture: 70mm
- Focal Length: 350mm, f/5
- Weight: 1.4kg
- Supplier: Altair Astro
- Telephone: 01263 731505
- Website: www.altairastro.com
This review originally appeared in the May 2018 issue of BBC Sky at Night Magazine