The Sky-Watcher Heliostar 76Ha refractor is a fresh new addition to the well-known manufacturer’s telescope line-up and its first venture into dedicated hydrogen-alpha instruments.
The spec is highly attractive, ambitiously promising ‘double-stack performance’ from a single etalon filter, while offering 76mm of aperture and a 630mm focal length, which is a great midway point between portability and detailed views of the Sun’s surface.
- Discover our pick of the best solar telescopes for safe observing of the Sun
By ‘double-stack performance’ we mean that the overall bandwidth of the light that is passed through is further reduced.
This allows for more solar contrast, as well as clearer views of fine surface detail and prominences.
Unboxing and setting up
The Heliostar 76Ha also comes with a host of accessories as standard, including a padded metal carry case, dual-speed focuser, solar finder, solar shield, 20mm eyepiece and smartphone mount.
The weather was unusually sunny, so we were able to put the Heliostar 76Ha to the test right away.
The instruction manual is accompanied by a sheet of safety precautions, the first of which emphasises that the refractor must always be used with the provided solar prism diagonal.
We assembled everything easily and, following the instructions, left the telescope outside for more than half an hour to acclimatise the etalon filter.
With its weight of 3.8kg, the Heliostar 76Ha will be easily carried by a wide range of mounts. For our review, we placed it on a ZWO AM5 harmonic drive mount.
Using the Sky-Watcher Heliostar 76Ha solar finder
When it was time to find and centre the Sun, we encountered a discrepancy in the instruction
manual.
The Sky-Watcher Heliostar 76Ha solar telescope manual refers to a non-existent ‘guider’ and the photos don’t correspond to the solar finder that comes with the telescope.
If anything, the solar finder on the Heliostar 76Ha is even better and easier to use than the one described in the instructions.
However, since this is highly specialised equipment designed to use safely while solar observing, we believe that the instructions should be clear and always correct, especially for those who may be using it for the very first time.
Finding the Sun using the solar finder was easy enough and soon it was time for our first look.
We used the 20mm eyepiece provided, which slotted into the diagonal and felt secure.
The dual-speed Crayford focuser is a wonderful touch on this assembly and focusing felt quick and incredibly easy.
However, the most impressive part that really sets this telescope apart from its current counterparts is the mechanical tuning motion.
It is done with an adjustment bolt at the top of the tube and instantly brought the Sun’s surface detail and prominences to life.
How the Sky-Watcher Heliostar 76Ha performs
The views in the Sky-Watcher Heliostar 76Ha solar telescope are nothing short of mesmerising.
Compared to single-stacked hydrogen-alpha telescopes that we have tried in the past, it instantly offered greater contrast and clarity.
We loved seeing well-defined solar prominences and solar flares, some even detached away from the chromosphere.
While the Heliostar 76Ha is primarily marketed for visual use, we wanted to test it for solar imaging.
We were pleased that it instantly came to focus with our ZWO ASI174MM camera, using the standard 1.25-inch nosepiece.
We did find that image results suffered from some unevenness, most likely due to light passing through the Heliostar’s etalon at angles greater than its designed acceptance angle.
When this happens, image quality reduces. Ideally, the ‘sweet spot’ for image quality (where all the light passing through is within the acceptance angle) would cover the whole solar disc.
However, it didn’t in this case which is a common issue in this type of instrument.
The size of the etalon is 40mm, explaining why it’s difficult to achieve a uniform ‘sweet spot’ across the whole disc.
However, larger etalons are very expensive and there must be a compromise between affordability and imaging performance.
Thankfully, with the help of the easy tuning motion, we were still able to capture some pleasing results.
The quality of images produced was undoubtedly excellent given the price bracket.
The Sky-Watcher Heliostar 76Ha solar telescope offers solar views of high quality, with instant ease of use and within a price we feel really can’t be beaten.
As our review period ended, we were sad to return it.
Etalon filter
The heart of the Sky-Watcher Heliostar 76Ha is the Solis 40mm etalon filter, tuned natively to <0.5 angstroms.
This means that the views of our nearest star are richer in contrast, showing beautifully clear details on the chromosphere and corona.
The Heliostar 76Ha promises a ‘double-stack’ performance in a single etalon and, while it’s impossible to measure whether it absolutely reaches the advertised bandpass, we were left very impressed with the views.
It undoubtedly offers more than single-stacked dedicated hydrogen-alpha telescopes.
Together with the mechanical Triffid tuner, the etalon filter provides an instantly satisfying viewing experience that would suit even complete solar beginners.
For experienced astrophotographers, it leaves room to take up solar imaging with good results and an easy set-up experience.
We should note that the Solis etalon must always be used with the Solar Zenith diagonal, as this is where the safety-crucial 11.5mm blocking filter is located.
Sky-Watcher Heliostar 76Ha best features
Sun shield
This is a simple yet practical addition to the whole assembly. Often you have to purchase a sun shield separately to prevent your camera or eyepiece from sitting in the Sun too long. It attaches easily and has felt fabric glued to the bottom so it won’t scratch the ceramic paint coating.
Integrated solar finder
Unlike other solar finders, this one is bolted on top of the anodised mounting rings. We were concerned about the possibility of it being misaligned, but it turns out there were no such issues and it was spot-on. Despite the inaccurate instructions, it was exceptionally easy to use.
Integrated tuner
The Heliostar 76Ha has a ‘Triffid’ mechanical pressure tuning system. The tuning pin is supported by three vanes to apply pressure to the etalon plates, meaning we were able to smoothly adjust our bandpass. While this is not a new design innovation, we haven’t seen these on the market for a while.
2-inch dual-speed focuser
A wonderful addition to the build quality of the telescope, this Crayford-style focuser
is easy to manoeuvre and use without introducing shaking to the views. We found that the tension thumbscrew needed some tightening out of the box. The focuser is placed perpendicularly to the Vixen-style dovetail and is compatible with electronic focusers.
Universal smartphone mount
This is one accessory we found less useful. We didn’t think it was as easy to use as higher-end mounts and because colour cameras can’t capture the hydrogen-alpha bandpass as we see it, the smartphone results were pale and underwhelming compared to monochrome cameras.
Vital stats
- Price: £2,399
- Optics: Achromatic doublet refractor
- Aperture: 76mm
- Focal length: 630mm, f/8.3
- Wavelength: 656.28nm
- Bandpass: <0.5 angstroms bandpass
- Focuser: 2-inch dual-speed Crayford
- Extras: Carry case, Vixen-style dovetail bar, 20mm eyepiece, sun shield, solar diagonal, smartphone adaptor
- Weight: 3.8kg
- Supplier: Optical Vision Limited
- Email: info@opticalvision.co.uk
- www.opticalvision.co.uk
This review appeared in the July 2025 issue of BBC Sky at Night Magazine
