Lunt Solar System H-alpha telescope:
This complete solar telescope is a high-quality achromat, with the front lens reducing stray light to half that of a standard achromatic objective. This eliminates possible coma, astigmatism, centering deviations and, together with the appropriate collimation lenses, makes a spherically-corrected flat-field solar telescope. The image is optimized for maximum sharpness in the red part of the spectrum. The optical system is shadow-free (no central obstruction) and is suitable for observing the Sun's surface, as well as for prominences. The tube is made of metal and has been painted white.
Filtering is via an Etalon system: 2 parallel plates made of transparent material, e.g. silica glass with a mirrored surface. Such a system has frequency-dependent, periodic transmission maxima and loss minima. The Etalon filter used by the Lunt Solar System telescope isolates a specific wavelength of the solar spectrum: the H-alpha line. The internal Etalon system with fine tuning allows observing over a better than 0.7 Angstrom bandwidth. With an additional double-stack Etalon filter, which can be mounted in front of the front lens of the telescope, a bandwith of less than 0.5 angstrom is achieved.
The sensitive and precise focusing is done by a high quality 2" Crayford Focuser with 1:10 reduction. So you have a visual as well as photographically full control and always a sharp picture, what is essential particular at the solar observation.
The solar telescopes of the LS35T series will be delivered according to the package with a variant of the following block filter (see delivery): B400 (4mm) or B600 (6mm). Please note that the operation without block filter is not possible and is extremely dangerous!
Properties of the optics:
Focal length: 400mm
Half width with an internal etalon filter:
Filed under: High-End Telescope Auctions (USA)