Lunt LS80MT Premium Plus Kit 80 mm H-Alpha Telescope with 0.35" Double Stack Filter

Lunt LS80MT/B1800 R&P Multipurpose APO Telescope for Sun and Night Sky

Modular designed multipurpose telescope, both for observing the sun in the H-alpha wavelength, as well as for night sky observations. Easy conversion between the different applications with a few simple steps. 2-element apochromatic telescope with FPL53 glass, 80 mm aperture and 560 mm focal length - excellent image quality for H-Alpha solar observation and also for observing the starry sky at night. Features an innovative air pressure tuning system, an additional double-stack filter for an FWHM of 0.28 Å (combined etalons), a 2"-rack-and-pinion focuser, and a B1800 blocking filter.

Solar observing in H-alpha
The LS80MT/B1800 is a complete telescope for observing the sun in H-alpha light, with 80 mm clear aperture (no central obstruction) and 560 mm focal length. The H-alpha wavelength is the most impressive way to observe the sun, showing prominences, filaments and flares on the surface, and much more. An internal etalon filter achieves a bandwidth of 0.45 angstroms using the innovative Pressure-Tuner air pressure tuning system. Tuning is done by slightly changing the air pressure in a pressure chamber inside the telescope. This changes the refractive index of the air, making it easy to tune to the H-alpha line. The pressure tuner guarantees a homogeneous image, without central obstruction, and a permanently protected etalon without wear. A set of collimating lenses installed in the telescope ensures best performance.

The LS80MT Premium Plus comes with an SFTP internal double-stack module, connecting two pressure-tuned etalons in series and reducing the system bandpass to <0.28 angstroms. The dual independent Doppler True pressure tuners give you complete control over bandpass optimisation.

Two pressure-tuned etalons working in series, each with its own tuning knob, each responding instantly to adjustment. The internal architecture maintains perfect optical alignment across the entire bandpass adjustment range. The result is sub-quarter-angstrom performance with the tuning flexibility that only dual pressure systems can provide. This makes even more details on the Sun´s surface visible, particularly in the chromosphere, with a level of precision never before achieved.

The blocking filter is the B1800. The B1800 is well-suited for visual solar observation as well as for solar photography with cameras equipped with small sensor chips. The Sun is imaged frame-filling through the blocking filter, including the prominences. It has a diameter of 5.6 mm at the focal point. The mirror diagonal, into which the blocking filter is built, comes standard with both a receptacle for 1.25-inch eyepieces and a T2 mount for cameras. The telescope offers sufficient back focus for all standard cameras.

What can you see on the sun:
At <0.28 Å combined bandpass through 80 mm of premium FPL53 ED optics, the chromosphere reveals structures that instruments with simpler optics cannot match at any aperture. Filaments resolve into fine details, and active regions display rapidly changing features due to the strong magnetic fields. The rapid changes in filaments are visible in real time. Prominences reveal intertwining structures and flow patterns with the highest resolution.

Observing the starry night sky
Thanks to its modular design, the H-Alpha Etalon system can be removed from the telescope in just a few simple steps. The 2-element ED apochromatic refractor can then be used as a standard telescope with an 80 mm aperture and 560 mm focal length for observation and photography of the night sky. The FPL53 doublet lens provides a beautiful, low chromatic aberration image. Common 2" star diagonals can be used on the focuser of the telescope.

Versatile eyepiece
The included 7.2-21.5 mm zoom eyepiece allows for continuous magnification from the entire star field down to detailed observation of active regions without the need to change eyepieces - a critical advantage during observations where conditions change and you need to switch between different objects and magnifications without missing a single moment.

More applications
With optional accessories, the LS80MT offers even more possibilities!
- White-light solar observation
Once the H-Alpha unit has been removed, you can, of course, use either a solar filter installed in front of the objective lens or a Herschel wedge on the focuser to observe sunspots in white light.
- Solar observing at the Ca-K wavelength
The separately available "Lunt Ca-K Module with B1200 Blocking Filter in Star Diagonal for 2" Focuser" (item number LS12CaKMDd2) or the "Lunt Ca-K Module with B1800 Blocking Filter in Star Diagonal for 2" Focuser" (item number LS18CaKMDd2) can be used with the LS80MT to observe and photograph supergranulation and other effects visible at this wavelength on the Sun.

This makes the LS80MT a truly versatile, top-quality apochromatic telescope!

Additional information: What is the "Pressure Tuner" system?
The air pressure in our atmosphere varies depending on whether you are at sea level or, for example, on a mountain. The different conditions influence the wavelengths of light. Although this shift is minimal, it is clearly visible with filter bandwidths of less than one angstrom. If the filter is no longer precisely adjusted to the (shifted) H-alpha wavelength, the image of the sun in the telescope becomes blurred, and prominences and surface details are no longer visible.

The etalon filter systems must therefore be adapted to the conditions prevailing at the observation site. This correction, known as "tuning", is usually achieved by mechanically tilting the filter. With dimensions of just a few angstroms, it is of course not easy to achieve the required correction precisely by tilting. Because the filter is then no longer exactly straight in the light path, optical errors can also occur.

The "Pressure Tuner" air pressure system from Lunt Solar Systems takes a different approach. The etalon filter is no longer tilted; instead, the air pressure in the filter system is changed. Starting from the ambient pressure at which the etalon is set to a red-shifted H-alpha line, the tuning system can be used to compress the air surrounding the etalon. This changes the refractive index and shifts the transmission wavelength toward blue, enabling precise adjustment to the actual current wavelength within a range of +/- 0.4 angstrom.
This allows for much more sensitive adjustment, and the surfaces of the etalon always remain at the correct angle in the beam path.

Safety informations: PDF Download