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IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
Lunt LS230THa Double Stack Solar Telescope - Pressure Tuned
Lunt LS230THa Double Stack Solar Telescope - Pressure Tuned

Lunt LS230THa Double Stack Solar Telescope - Pressure Tuned

by Lunt Solar Systems
SKU LSS-LS230THa/B3400
$39,995.00 - $39,995.00
$39,995.00
$39,995.00 - $39,995.00
$39,995.00
Price Match Policy!
  • 230mm Unobstructed Aperture
  • 1,610mm Focal Length (f/7)
  • Internal Double-Stack Etalon System (~0.30Å Bandpass)
  • Dual PC-USB Pressure Tuner Controllers
  • B3400 Blocking Filter (34mm Clear Aperture)
  • Starlight Instruments 2" Feather Touch Focuser
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Downloads
  • Warranty

  • Lunt LS230THa Double Stack Solar Telescope - Pressure Tuned

    The Lunt LS230THa is built around a 230mm f/7 FLP51 air-spaced doublet objective, establishing it as the largest commercially available H-alpha solar telescope in the world. Its internal, double-stacked etalon system achieves a combined bandpass of approximately 0.30Å for maximum chromospheric contrast. The optical train terminates with a B3400 blocking filter, providing a 34mm clear aperture to illuminate large-format sensors at the scope's native 1,610mm focal length. This instrument is one of only five units ever to be produced.

    The World's Only 230mm f/7 Solar Refractor

    At 230mm of fully unobstructed aperture, the LS230THa is an instrument without peer. The f/7 FLP51 air-spaced doublet objective is optimized from design to coating for the hydrogen-alpha wavelength of 656.28nm. The front element features a custom IR reflective coating that removes the bulk of solar thermal energy before it enters the optical tube, ensuring thermal stability for the precision etalons that follow.

    This uncompromising focus on solar observation makes the LS230THa entirely unsuitable for night-sky use. It is a dedicated instrument designed to deliver the highest-resolution view of the solar chromosphere possible, limited only by the Earth's atmosphere—not its own optics.

    Hand-Matched ~0.30Å Double-Stack Etalon System

    The LS230THa is double-stacked as standard. The system pairs a 0.6Å etalon with a new-generation 0.35Å etalon, with the final combined bandpass for each of the five instruments verified at ~0.30Å. This is not a simple addition; each etalon pair is hand-matched and individually tested to ensure the combined system achieves peak uniformity and contrast across the full 230mm aperture.

    The result is a view where chromospheric structures are rendered with definitive contrast. Filaments resolve into dark, multi-strand systems, active regions show clear fibril organization, and prominences at the limb reveal intricate internal threading and flow patterns.

    HRG Filter and B3400 for a 34mm High-Contrast View

    Integral to the LS230THa's optical path is a High Resolution Glass (HRG) filter. This component eliminates the off-band solar continuum glow that can wash out faint details, producing a genuinely dark background. This maximizes the perceived contrast and three-dimensional texture of the chromosphere.

    The light path terminates in an internal, Lunt-modified B3400 blocking filter. With 34mm of clear aperture, it fully illuminates even large imaging sensors, preventing vignetting and ensuring the entire 16mm solar disk image is delivered to the focal plane with maximum brightness and uniformity.

    Dual PC-USB Controllers for 0.3 PSI Doppler Precision

    At this aperture, remote control is essential. The LS230THa includes two PC-USB Pressure Tuner Controllers—one for each etalon—that allow for vibration-free tuning with an accuracy of 0.3 PSI. The system provides closed-loop feedback, automatically compensating for temperature changes to maintain a stable wavelength position.

    This system transforms Doppler tuning from an art into a reproducible science. You can scan both etalons in tandem from the red to the blue wing of the H-alpha line, maintaining the ~0.30Å bandpass throughout. By recording the precise pressure values for specific line positions, you can return to them with 0.3 PSI repeatability, session after session, enabling systematic and calibrated studies of solar plasma velocities.

    A 1,610mm Focal Length Imaging System

    The LS230THa's 1,610mm focal length produces a solar image nearly 16mm in diameter, an ideal scale for capturing high-resolution detail with modern sensors. The mechanical backbone is a Starlight Instruments 2" Feather Touch focuser with 10:1 fine focus reduction, providing the precision required to achieve critical focus at this image scale.

    For the advanced imager, the dual PC-USB control system is the key to unlocking the telescope's full potential. It enables calibrated, repeatable Doppler imaging sequences that were previously the domain of professional observatories. This makes the LS230THa the most capable solar imaging platform available to the public for studying the dynamic, fast-moving events that define solar activity.

  • Why is the Lunt LS230THa unsuitable for night sky observing?

    The Lunt LS230THa is a dedicated solar telescope. Its entire optical system, from the IR-reflective coatings on the objective to the internal etalons and blocking filters, is designed to transmit light only at the 656.28nm hydrogen-alpha wavelength and reject all other light. This design makes it impossible to see stars, planets, or galaxies.

    What is the advantage of the Lunt LS230THa's dual PC-USB pressure tuners over manual knobs?

    At the 230mm aperture and 1,610mm focal length of the LS230THa, even the slightest touch to the telescope introduces vibrations that degrade the image. The PC-USB controllers allow for remote, vibration-free tuning. They also offer superior precision (0.3 PSI accuracy) and repeatability, enabling scientific-grade Doppler velocity studies by allowing you to return to exact bandpass positions across multiple observing sessions.

    How does the Lunt LS230THa's ~0.30Å bandpass help when imaging a solar flare's Doppler shift?

    A solar flare involves plasma moving at high velocity toward or away from you. The narrow ~0.30Å bandpass allows you to isolate these movements with extreme precision. Using the PC-USB tuners, you can scan off the central H-alpha line into the "blue wing" (for approaching plasma) or "red wing" (for receding plasma), capturing the full velocity structure of the event with maximum contrast and detail.

    What does 'seeing-limited' mean for an observer using the Lunt LS230THa?

    The LS230THa is capable of resolving details so fine that on most days, the limiting factor will be atmospheric turbulence ("seeing"), not the telescope's optics. The instrument will regularly outperform what the sky allows. On days of exceptional seeing, it will resolve the finest structures visible from the ground, such as individual spicules at the solar limb and supergranulation cell boundaries.

    With the Lunt LS230THa and B3400 blocking filter, can I image the entire solar disk on a full-frame sensor?

    Yes. The Lunt LS230THa produces a solar disk image of approximately 16mm at its focal plane. The B3400 blocking filter has a 34mm clear aperture, which is more than large enough to pass the entire image without vignetting. A full-frame sensor (typically 36mm x 24mm) will easily capture the entire solar disk with plenty of room to spare.

    Why does the Lunt LS230THa use two different etalon generations (0.6Å and 0.35Å)?

    Combining etalons of different specifications is a complex optical challenge. For the limited run of the Lunt LS230THa, Lunt's engineers hand-matched a 0.6Å etalon with a new-generation 0.35Å unit to achieve the target combined bandpass of ~0.30Å. Each of the five systems required a unique matching process to find the optimal pair that would deliver consistent high-contrast performance across the entire 230mm aperture.

  • SKU LS230THa/PT/B3400
    Aperture 230mm (Unobstructed)
    Focal Length 1,610mm
    Focal Ratio f/7
    Objective Lens FLP51 Air-Spaced Doublet
    Etalon System Internal Dual Pressure-Tuned
    Bandpass ~0.30Å (Combined)
    Tuning Dual PC-USB Pressure Tuner Controllers
    Blocking Filter B3400 with 34mm Clear Aperture
    Focuser Starlight Instruments 2" Feather Touch with 10:1 Reduction
    Image Size at Focal Plane ~16mm
    Power 12-15V DC or 120/240V AC (for controllers)
    Controller Battery Life 12+ Hours
    Production Limited Edition (5 Units Total)

    • LS230THa 230mm H-Alpha Telescope OTA

      × 1

    • PC-USB Pressure Tuner Controller

      × 2

    • Observatory-Grade Tube Rings

      × 1

    • Mounting Plate

      × 1

  • Lunt Solar Systems 5-Year Warranty