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ApertureBuy the right telescope, not the biggest one

Instrument class

Dedicated hydrogen-alpha solar telescope

A small refractor built around an etalon that passes one wavelength of red light and nothing else. Prominences standing off the limb, filaments across the disc, and a Sun that changes by the hour. The most expensive 40 mm of aperture you will ever buy, and the one most likely to make you say something out loud.

Specifications for this class
Aperture40–60 mm
Focal ratiof/8–f/12
Typical weight2 kg
Setup time5 minutes
Learning curve2 out of 5
Price band€1100–2500
Useful magnification8× to 100× at 50 mm

What it does well

  • Prominences, filaments, plages and flares — the living Sun, not the flat disc white light shows
  • Changes visibly over an afternoon, which nothing else in the sky does
  • Small, light, and the target is up in daytime

What it costs you

  • It shows the Sun. It shows nothing else, ever, at any price — there is no night-time use
  • Tune-able etalons are a skill, and the view on a mistuned one is a disappointing red disc
  • A 40 mm costs what a 250 mm Dobsonian costs. Be certain the Sun is what you want before this is what you buy

Fit against each goal

  • The Sun · 5 out of 5

    This is what the instrument exists for. Nothing else on this list comes close.

  • Taking it with me · 4 out of 5

    One tube on a photo tripod. Solar observers take these on holiday.

  • Sharing it with children · 3 out of 5

    Prominences hold a child's attention like nothing at night does, but the tuning is an adult's job and the price is a real commitment.

  • First astrophotography · 3 out of 5

    Solar imaging with a phone at the eyepiece is surprisingly good, and a dedicated camera turns it into a genuine speciality.

  • Learn my way around the sky · 0 out of 5

    There is one object, and the instrument cannot see any other.

  • The Moon and the planets · 0 out of 5

    Never. The etalon passes one wavelength of sunlight and blocks everything else, including the Moon.

  • Nebulae, clusters and galaxies, by eye · 0 out of 5

    Never.

Models in this class

Indicative European street prices with the date they were observed. Ordered by price. Links marked earn us a commission and cost you nothing extra.

  • Lunt Solar Systems LS40THa B500

    €1290seen 2026-08-22

    40 mm · 400 mm focal length · f/10.0 · 1.2 kg

    With a 10 mm eyepiece: 40×, 1.0 mm exit pupil.

    Mount Optical tube only — mounts on any photo tripod via a 1/4" thread — not included

    The current entry point to hydrogen-alpha since the Coronado PST went out of production. The B500 blocking filter suits visual use; imaging wants the B600 or larger. Needs a tripod you already own.

    Where to buy

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