Best solar telescopes, perfect for observing an eclipse
Our pick of the best telescopes for safely observing the Sun.
By Iain Todd
Published: Wednesday, 04 October 2023 at 10:09 AM
When observing with the best solar telescopes, the Sun becomes arguably the most dynamic and interesting object to observe in the sky.
Solar telescopes use an etalon, which is a precision filter that restricts the light that enters the telescope (allowing, for example, only H-alpha to pass through), so you can safely observe the Sun up-close.
Details on the Sun such as solar prominences, filaments, plage and fibrils become startlingly visible when using a solar telescope.
It goes without saying that observing the Sun with anything other than a certified solar telescope or certified solar filter is incredibly dangerous, and will seriously damage your eyesight.
You should only use well-made solar telescopes from reputable suppliers – accept no substitutes!
This is our list of some of the best solar telescopes available, and links to where you can buy them online.
The Lunt LS152THa is a 6-inch hydrogen-alpha (h-alpha) telescope, which is huge by h-alpha standards.
The telescope is designed for safe solar observing and reveals one of the Sun’s inner layers, called the chromosphere.
The LS152THa is extremely well-engineered and solidly built.
It’s brilliant at showing you fine detail in and above the chromosphere, while also revealing bright and structurally detailed prominences.
While testing the telescope, we were able to observe some active sunspot regions and found the zoom eyepiece allowed us to get a close look at the action.
We saw plenty of surface detail and very good resolution.
We were also able to easily observe a layer of hydrogen plasma jets, called spicules, at the edge of the Sun.
The Lunt LS152THa is a fantastic telescope that effectively gives you a solar observatory in your back garden.
Key specs
Focal length: 900mm; f/6
Aperture: 152mm (6 inches)
Bandpass: <0.065nm at 656.28nm (h-alpha); 0.24nm at 393.4nm (calcium-K)
The Coronado Personal Solar Telescope has a quoted bandpass of less than 1 Angstrom (Å), which makes it great for revealing prominences and surface detail.
During testing, the PST delivered a very acceptable view.
We found prominences appeared bright, detailed and with good contrast against the background sky.
There was amazing detail on the edge of the Sun and a distinctly fur-like appearance.
This was the presence of spicules, short-lived plumes of glowing hydrogen gas.
The PST also revealed well-defined active regions and filaments with buckets of intricate detail.
We also found excellent results during imaging.
This budget H-alpha solar observing classic continues to deliver low-, medium- and high-magnification views of the Sun.
It should be pointed out from the offset that the Bresser Solarix 76/350 telescope is not a dedicated solar observing telescope, but comes with a solar filter that makes solar observing possible.
It is an interesting, multi-purpose offering that’s really only suitable for beginners or those after a budget telescope.
Solar observing is just one facet of the Bresser Solarix 76/350, and it’s aimed at beginners who want to try out some of the different aspects of astronomy with just one piece of equipment.
It’s comprised of a 3-inch (76mm) Newtonian reflector atop an aluminium tripod with a manual push-to mount.
The telescope includes a decent collection of accessories including 20mm and 4mm eyepieces, a 2x Barlow lens, a smartphone adapter and, importantly here, a certified solar filter.
Setting up is quick and easy and converting the Bresser Solarix 76/350 telescope to solar use is simple. You just need to attach the front-mounted solar filter.
The solar-use instruction manual and the many safety stickers on the Solarix do a good job of informing the user how to safely observe the Sun.
It won’t give you amazing views of the Sun like other solar scopes on our list, but is suitable for beginners or kids who want to take their first seps into the world of astronomy, solar or otherwise.
Key specs
Optics: 76mm (3 inches)
Focal Length: 350mm (f/4.6)
Extras: 4mm and 20mm eyepieces, 2x Barlow lens, solar filter, smartphone photo adaptor, accessory tray
The Double-Stacked Personal Solar Telescope may look similar to the PST, but it has a second etalon screwed into the front lens cell.
This arrangement further reduces the telescope’s bandpass to 0.5Å, increasing the definition of surface features such as dark filaments and bright plage areas.
One downside to this reduction in bandpass is a reduced visibility of prominences.
Indeed, during our tests we did notice a slight dimming, but bright prominences were still impressive.
The visual performance of the DS PST was definitely something to shout about.
This is a superb scope, ideal for increasing the visibility of subtle features that wider bandpass instruments may struggle with.
When we test each solar telescope, we examine the following features.
Accessories
There aren’t many peripheral bits and bobs needed with solar scopes, but a good finderscope and mounting plate are among those that we consider essential. We tried out those supplied and found out how good they were.
Construction
Looking fantastic, as all these scopes do, is no substitute for good design and this is something that can only be assessed when they’re being used. We wanted to know whether the design would help or hinder when put to use.
Field of view
A common issue with many solar scopes is the sweet-spot effect whereby features pop in and out of visibility depending on where they are in the field of view. We evaluated the uniformity of each scope’s field, keeping an eye on feature contrast.
Focusing
We looked through each scope to evaluate how easy it was to find the Sun, achieve focus and tune the etalon to give us the best view possible. We also assessed how comfortable the view was after long observing sessions.
Imaging
We hooked a high frame-rate planetary camera up to each scope to find out just how image-friendly they were. We also took a number of shots of the same objects through each scope and compared the processed results.
