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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.
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 40mm Solar Telescope

Lunt 40mm Solar Telescope

by Lunt Solar Systems
SKU LSS-LS40THa/B600
$895.00 - $995.00
$907.00
$895.00
$749.00 - $995.00
$895.00
Price Match Policy!
  • 40mm Aperture
  • 400mm Focal Length (f/10)
  • ~0.65 Angstrom Bandpass
  • External, Tilt-Tuned Etalon
  • Multiple Blocking Filter Options (B500, B600, B1200)
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Downloads
  • Warranty

  • Lunt 40mm Solar Telescope

    The Lunt 40mm Solar Telescope delivers high-contrast views of the solar chromosphere through a 40mm doublet refractor optical system with a 400mm focal length. Its front-mounted, tilt-tuned etalon achieves a narrow ~0.65 Angstrom bandpass, resolving fine details like solar prominences and surface filaments. This design produces a solar image size of ~3.67 mm, which can be optimized for visual or imaging use by selecting the appropriate blocking filter diagonal (B500, B600, or B1200).

    A ~0.65Å Bandpass from a 40mm Front-Mounted Etalon

    The core of the Lunt 40mm is its unobstructed 40mm external etalon. Placing the filter at the front of the 400mm focal length optical path ensures even illumination and thermal stability. The ~0.65 Angstrom bandpass is significantly narrower than competing entry-level solar scopes, allowing you to see prominences and surface detail with enhanced contrast against a dark sky background. Tuning is accomplished by tilting the etalon, shifting the bandpass to zero in on specific features in the 656.28 nm H-alpha line.

    B500, B600, and B1200 Blocking Filters for Visual and Imaging

    The blocking filter is a critical second stage in any H-alpha system, and the Lunt 40mm integrates it directly into the star diagonal. The choice of blocking filter determines the unvignetted field of view around the ~3.67 mm solar disk. This OTA is available with multiple blocking filter sizes to match your observing goals.

    • B500 / B600 Filters: These options are ideal for visual observation, providing a generous field around the Sun to frame prominences without introducing unnecessary cost.
    • B1200 Filter: Recommended for imagers, the larger 12mm aperture of the B1200 provides a much wider, fully illuminated field of view. This prevents vignetting on the larger sensors common in modern solar system cameras.

    Helical Focuser with a 1.25" FeatherTouch Upgrade Path

    Out of the box, the Lunt 40mm includes a robust helical focuser. This mechanism is simple, compact, and holds focus well, making it ideal for a portable grab-and-go instrument. For users seeking the highest level of precision, the focuser is directly upgradeable to a 1.25" Starlight Instruments FeatherTouch focuser, a common standard for premium astronomical equipment. This provides a clear and simple path to improving the telescope's mechanical performance without requiring custom adapters.

    Lunt 40mm vs. Coronado PST: A Tighter ~0.65Å Bandpass

    The primary competitor to the Lunt 40mm is the Coronado Personal Solar Telescope (PST). While both are 40mm H-alpha telescopes, they differ in key design areas. The PST's main advantage is often its lower price point.

    The Lunt 40mm, however, offers a distinct optical advantage with its ~0.65 Angstrom bandpass, which is significantly narrower than the PST's specified <1.0 Angstrom bandpass. This tighter bandpass directly translates to higher-contrast views of solar surface features. Additionally, the Lunt's external etalon design and the ability to upgrade to a FeatherTouch focuser provide a higher performance ceiling for serious observers and imagers.

  • What solar features can I see with the Lunt 40mm Solar Telescope?

    With its ~0.65 Angstrom bandpass, the Lunt 40mm is designed to show details in the Sun's chromosphere. You can expect to clearly see solar prominences (eruptions at the limb), filaments (dark ribbons crossing the surface), active regions, and some surface granulation.

    What is the difference between the B600 and B1200 blocking filters on the Lunt 40mm?

    The blocking filter size determines the size of the illuminated field of view around the Sun.

    • The B600 (6mm) is excellent for visual use, providing enough space to frame the solar disk and any surrounding prominences.
    • The B1200 (12mm) is recommended for imaging. Its larger aperture prevents the edges of your camera sensor from being darkened by vignetting, ensuring an evenly lit image.

    How will the Lunt 40mm perform when viewing a large solar prominence?

    The Lunt 40mm is an excellent instrument for prominence viewing. The ~0.65Å bandpass provides a dark background, making faint prominence details stand out. The tilt-tuning mechanism allows you to slightly shift the wavelength to brighten the prominence against the blackness of space, revealing delicate loop and arch structures.

    Can I use a high-frame-rate camera with the Lunt 40mm Solar Telescope?

    Yes. The Lunt 40mm is suitable for imaging with modern solar system cameras. For best results, it is highly recommended to choose the B1200 blocking filter option. This will provide an unvignetted field for most standard 1.25" format imaging sensors, allowing you to capture the entire solar disk without dark corners.

    Why would I choose the Lunt 40mm over the Coronado PST?

    The primary reason is optical contrast. The Lunt 40mm's ~0.65 Angstrom bandpass is significantly narrower than the PST's <1.0 Angstrom specification, resulting in more detailed views of surface features like filaments. The Lunt also offers a direct upgrade path to a premium 1.25" FeatherTouch focuser, a significant mechanical advantage.

    Is the helical focuser on the Lunt 40mm difficult to use?

    The helical focuser is very straightforward. It operates by twisting the eyepiece holder to move the eyepiece in and out. While it may not offer the fine control of a dual-speed Crayford, it is robust, holds focus well, and is very compact, which is a benefit for portability and travel.

  • Aperture 40 mm
    Focal Length 400 mm
    Focal Ratio f/10
    Optical Design Doublet refractor optimised for 656.28 nm
    Etalon External, front mounted, tilt tuned
    Bandpass ~0.65 Angstrom
    Blocking Filter Integrated into diagonal; B500, B600, or B1200 options available
    Solar Image Size ~3.67 mm (with 5 mm blocking filter)
    Focuser Helical, upgradeable to a 1.25" FeatherTouch
    Product Number LS40 OTA Only
  • Lunt Solar Systems 5-Year Warranty