Lunt 60mm H-Alpha Telescope w/ Double-Stack 50mm Filter, B600, Crayford Focuser & Pressure Tuner
Complete H-Alpha Solar Telescope with 60mm aperture and an additional 50mm Double-Stacked Etalon System. The telescope can be used with <0.75 Angstrom bandwidth or with <0.55 Angstrom bandwidth. With new air-pressure tuning system!
This telescope will be delivered with two matched Etalons, a internal one and a external. The internal etalon with new air-pressure tuning system adjustment allows for a <0.7 Angstrom bandwidth. This "Pressure Tuner" system allows a better Etalon adjustment than other systems. The “Pressure Tuner” system adapted the Etalon to varying altitudes and atmospheric pressures for always optimal performance. The LS60THaDS50 could be used only with the internal H-alpha filter at <0.7 Angstrom and a aperture of 60mm, or together with the front mounted external H-alpha filter at <0.5 Angstrom bandwidth and 50mm aperture.
The best views of the Sun are undoubtedly seen thru a dual etalon system. The reduction in bandwidth from an estimated 0.7 Angstrom to 0.5 Angstrom just seem to bring the Sun's surface to life. Adding a second etalon to an existing etalon is not quite as simple as it may seem. Both etalons need to be brought on line (matched) and both need to be adjustable (Tuning) such that all ghosts are eliminated. Ideally the transmission curves should overlap perfectly when on band to provide for the best possible resolution and contrast. Both etalons in this system will be matched at the factory in order to provide a system that is both optimized for performance and the elimination of ghosting.
The focal length of the telescope is 500mm, Blocking Filter is the B600. The star diagonal in which the blocking filter is installed, is equipped as standard for 1.25" eyepieces and with a T2 camera connection. Fine adjustment is achieved with a Crayford style focuser with 10:1 reduction standard.
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LS60THa/B600FT Technical specifications (double stacked version):
- Aperture: 60mm or 50mm
- Bandwidth: <0.75 Angstrom or <0.55 Angstrom
- Tuning: tiltable Etalon
- Focal Length: 500mm
- Blocking Filter: B600 with 1.25" and T-2 connection
- Colour: Pearl White with Black Anodised Accents
- Focuser: Starlight Instruments Feather Touch with 10:1 reduction
- Storage: die cut foam with room for accessories (optional aluminium case available)
- Mounting: tube rings (optional dovetail plate available, see below recommended accessories)
- Tube length: 47cm
- Weight without rings: 3.8kg
- LS60T Hydrogen-alpha Solar Telescope with 60mm aperture and Internal Etalon
- B600 Blocking Filter in star-diagonal for enhanced viewing
- LS50FHa External 50mm Double-Stack Etalon
- Starlight Instruments 2" Featehr Touch Dual-Speed Focuser
- Tube Ring with 1/4"-20 connection for mounting on photo-tripods
- Transporting case with die cut foam with room for accessories
Recommended (and suitable) accessories:
The LUNT Zoom Eyepiece with variable focal length from 7.2mm to 21.5mm, with 1.25" connection.
Sol-Searcher for mounting on all solar telescopes of Lunt Solar Systems. The tube rings of the LUNT solar telescopes are prepared for the mounting of this Sol-Searcher.
LUNT Dovetail Plate with 100mm length. The telescope connecting screws are 1/4-20 inch size and they do not look out of the rail, which makes this rail a perfect match for Vixen like and similar mounts.
General information about the LUNT LS60THa double stacked 60mm solar telescopes
LS60THaDS50 Double Stack Telescopes
These telescopes with their 60 mm aperture and 500 mm focal length provide a very detailed resolution for observing and imaging the sun. However, with a weight of approximately 3 kg the telescopes can easily be carried by most photo tripods. The tube rings of these telescopes are fitted with a 1/4”-20 thread for mounting it on such tripods. The sensitive Etalon systems are well protected in the telescope tube installed and provide a bandwidth of <0.75 Angstrom. A integrated matched collimation lens set fully corrects on axis coma, astigmatism, and de-centering aberrations and provide a full spherically corrected flat-field solar telescope.
We offer these telescopes alternatively with our B600 or B1200 blocking filter to you. The larger B1200 blocking filter will be better for imaging, because it provides a smaller vignetting.
Normally these telescopes are equipped with a 2” Crayford focuser with 10:1 reduction. They are also available with the legendary Starlight Instruments Feather-Touch focuser, one of the best focuser in the world. Certainly also with 10:1 reduction.
All versions come with a robust aluminum-case as part of the standard package.
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.