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Lunt 152mm H-alpha Solar Telescope Feather-Touch Focuser and Pressure Tuner

Lunt 152mm H-alpha Solar Telescope Feather-Touch Focuser and Pressure Tuner
Our Price:  £11,009.00(Inc. 20% VAT)

Model:  L0551501
Brand:  Lunt
Telescope Type:  Solar Telescope

A 6” refractor for solar observing: 152 mm aperture, 900 mm focal length, 100% unobstructed, and a bandwidth of <0.65 Angstrom - the solar telescope for professionals!

If it is the perfect solar image you are after, than the LS152THa is the right system for you. It provides a large image size and high resolution. The system will perform to the highest level at any magnifications. Utilizing advanced hi-contrast coatings and the new air-pressure tuning system “Pressure Tuner”, the user will be able to experience crisp, sharp, high-magnification visual and digital images.

Certainly these high end telescopes are equipped with high end accessories. The alternatively with B1200, B1800 or B3400 blocking filter equipped telescopes will be delivered with tube rings, dovetail plate, zoom eyepiece 7.2 to 21.5 mm, transport case and Starlight Instruments Feather-Touch focuser.

Also available for the LS152THa is an additional Calcium-K module (LS152TCaKMD, article no. L0551590). This can easily replace the standard H-alpha module in a few steps, so you can observe and image the sun with only one telescope alternatively in H-alpha light or in the wavelength of Ca-K!

Delivered in the Box

  • H-alpha Telescope with internal Etalon and 152mm Aperture
  • Pressure Tuner system
  • B1200 or B1800 or B3400 blocking filter in star-diagonal
  • Starlight Instruments 2" Feather Touch focuser
  • Tube Rings with dovetail
  • LUNT Zoom-Eyepiece
  • Transport case

What is the „Pressure Tuner“ system?

The air pressure of the atmosphere varies, depending on if you are at sea level or on a mountain. Unfortunately also the sensitive Etalon filter systems respond to these air pressure variations. The wavelength range that is allowed through the filters, shifts as a function of the air pressure. This shifting is indeed minimal, but at bandwidths of less than one Angstrom it is already clearly visible. If the filter is not adjusted precisely to the H-alpha wavelength, the image of the sun through the telescope degrades, prominences and surface details are no longer visible.

Therefore, the Etalon filter systems have to be adjusted to the prevailing air pressure at the observation location. This “Tuning” called adjustment is typically done by a mechanical tilting of the filter. At sizes of a few Angstrom, it is obviously not easy to achieve the exact adjustment by mechanical tilting. And because the filter is no longer perfectly straight in the beam path, but slightly oblique, there may also be optical failures.

The new air-pressure system “Pressure Tuner” by Lunt Solar Systems takes a different path. The Etalon filter will not be tilted to only simulate a balance to the air pressure, but the air pressure in the filter system is in fact adapted by 100 percent to the real external air pressure. Thereafter the air surrounding the Etalon can simply be compressed or decompressed by the tuning system in order to change the air pressure between the surfaces. This allows the Etalon surfaces to always remain at the same perfect angle to the light waves but changes the diffractive index of the air in the chamber and thus accomplishes the same tuning expect that it goes around + or - 0.4 Angstrom on either side of the centerline. Therefore, the patent-pending “Pressure Tuner” system from Lunt Solar Systems is also called “True Doppler Tuning”, and it achieves much better results than conventional tuning systems.

Technical data:


  • Type: Single Interference HD Etalon
  • Tuning: air-pressure tuning system
  • Aperture: 152mm
  • Focal Length: 900mm
  • Focal Ratio: F6
  • Bandwidth: <0.65 Angstrom @ 656.28nm
  • Focuser: Starlight Instrument Feather Touch
  • Color: Pearl White with Black and Red accents
  • Weight: 14 kg
  • B1200 or B1800 or B3400 Blocking Filter (optimal for imaging with big CCD chips)

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Related Products
Ca-K Module for the LS152THa Telescopes

Ca-K Module for the LS152THa Telescopes£2,143.00

The LS152THa telescopes could be upgraded with a optional, interchangeable Ca-K module allowing for the research of multiple wavelengths through the same telescope.