Lunt 100mm H-alpha Solar-Telescope with B1200 blocking filter


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The Lunt LS100THa/B1200 100mm solar refractor represents a new approach to serious high resolution Hydrogen-alpha solar viewing, with stunning high resolution views of solar prominences, flares, and subtle disk details. A new coating standard, as well as a revolutionary air pressure tuning system, allows solar views that will take your breath away.

Our Product #: L100T
Lunt Solar Systems Product #: LS100THa/B1200
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Product Description

The Lunt 100mm solar refractor shows you much more of the living Sun than ordinary glass or Mylar white light solar filters that show only sunspots. With the Lunt LS100THa/B1200, you see the violent ever-changing tapestry of multiple prominences leaping off the edges of the solar disk and the explosive upheavals of flares and filaments on the face of the Sun. All of this is visible in addition to sunspots, faculae, and solar granulation in exquisite detail.

The Lunt LS100THa/B1200 consists of an 800mm focal length 100mm aperture f/8 refractor with an integrated Hydrogen-alpha solar filter. The two-part filter uses an internal etalon midway between the objective lens and the diagonal and a 12mm aperture blocking filter built into the standard equipment 2" star diagonal with 1.25" adapter that is mounted in the genuine 2" Feather Touch dual-speed Crayford focuser.

The 100mm Lunt has a revolutionary air pressure tuning mechanism built into the etalon. The air pressure tuning system allows the end user to make very subtle, yet crucial, adjustments to the solar image more easily than any coarser manual tilt tuning mechanism. The subtle tweaks that the air pressure tuning system allows can vastly improve the contrast and turn your observing experience from merely very nice to simply incredible.

The scope's 100mm diameter singlet objective lens is fully multicoated. It is not necessary to use an achromatic doublet in a solar scope to correct for chromatic aberration in the violet end of the visible spectrum. Solar scopes are designed to observe only a single wavelength of red light at the opposite end of the spectrum. Why pay for two lenses to cure a problem that a solar scope is incapable of showing you in the first place? In addition, the front singlet lens design reduces the stray light of a two-lens achromat by 50%. With the matched collimation lens set built into the scope, it also fully corrects for on-axis coma, astigmatism, and de-centering aberrations and provides a spherically corrected flat-field image.

The filter has a <0.7 Ångstrom passband, centered on the 6562.8 Ångstrom H-alpha line. The sub-Ångstrom passband width gives you balanced views of feathery prominences and low-contrast surface detail alike. The filter is thermally stable, so there is no drifting off the H-alpha line as the filter heats up during use. The 12mm clear aperture of the blocking filter portion of the H-alpha system (which is built into the star diagonal housing) is ideally matched to the focal length of the telescope to give you a large 7.3mm diameter image of the full disk of the Sun at prime focus, with a 1.16 arc second resolution that will let you see amazing amounts of surface and prominence detail.

Focusing is done using the supplied dual-speed high precision Starlight Feather Touch Crayford focuser . This 2" focuser has 2.5" of focuser travel and a separate 10:1 reduction ratio fine-tuning knob for precision focusing on the smallest of solar details. Large ribbed focusing knobs make it easy for you to reach a precise focus, even if you are observing in the dead of winter while wearing gloves or mittens.

You can use virtually any 1.25" eyepieces with the 100mm Lunt solar refractor. However, a high quality, high contrast, flat-field eyepiece such as a Plössl will give you the best results. For example, a typical 20mm 1.25" Plössl will give you a magnification of 40x and a little over a 1.25° field of view compared with the 0.5° diameter disk of the Sun. A 15mm Plössl will give you 53.3x and about a 0.93° field, giving you plenty of dark sky background around the 0.5° diameter solar disk to show off the prominences.

The Lunt LS100THa/B1200 comes with a TeleVue-style clamshell mounting ring with 1/4"-20 thread holes that will let you mount the scope directly on a photo tripod for a quick peek at the Sun. You can also mount the clamshell ring on a dovetail plate and install it on an altazimuth mount with slow motion controls for easier extended observing and tracking of the Sun. A foam-lined hard case is standard equipment for transporting and storing your Lunt scope.

Tech Details

Aperture 3.9"
Binary and Star Cluster Observation No
Focal Length 800mm
Focal Ratio f/8
Galaxy and Nebula Observation No
Lunar Observation No
Planetary Observation No
Resolution 1.16 arc seconds
Warranty 1 year


Review by:
I purchased this solar refractor earlier this year. Even though we are experiencing a solar minimum, this scope is providing me with tremendous views of proms , a few sun spots and filaments. For viewing the sun in Hydrogen-alpha, Lunt is the way to go. This year, I have imaged animation of proms and ISS solar transits. Awesome! (Posted on 7/22/2019)
Review by:
I’ve owned this scope for a year. I find that it is large enough to show spicules and fine details visually. But it’s a breeze to set up. I use it on an alt-az for a quick session as well as on a GEM for longer sessions. The views through a binoviewer are the best. I can spend hours. I’m getting into imaging and creating animations and this scope performs quite well with the B1200 and Feathertouch focuser configuration. I’m looking forward to many more years of enjoyment. (Posted on 11/12/2018)
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Supplied Accessories

  • Tube ring
  • B1200 blocking filter
  • Hard case