Lunt Solar Systems LS100THa 102mm f/7 Refractor Solar Telescope, OTA only

The Lunt Solar Systems LS100THa is a complete solar telescope. This refractor-based system has a precision-aligned singlet chromatic lens with a 102 mm aperture. The front singlet lens reduces the stray light over an achromat by half. With the matched collimation lens set, it also fully corrects on-axis coma, astigmatism and de-centering aberrations, and provides a full spherically corrected flat-field solar telescope. The focal length is 714 mm, for an f/ratio of 7. Course focus adjustment is via a slide tube. Focusing is achieved with a high precision 2" Starlight Feather Touch focuser with 10:1 reduction as standard equipment. An internal etalon with tune adjustment allows for a <0.7 Angstrom bandpass.

True Doppler Tuning allows for a shift into and away from the user, adding a 3-D like component to the viewing experience. While it has minimal effect on proms due to their location at the edge of the disk, it does have an effect on filaments and active regions on the surface. While looking at a filament at the center of the Sun, the user has the ability to Doppler shift from the base of the filament to the tip, following the filament through it s structure toward you and away from you, allowing for enhanced visual and imaging capability for the observer as well as a research tool for the avid hobbyist. The pressure tuning system provides an order of magnitude more precision to the tuning of the desired features.