LUNT 230mm H-a Telescope, B3400, 2.5" Feather Touch focuser, Pressure Tuner

• Only on request

LUNT LS230THa/B3400

Complete H-alpha Solar Telescope with 230mm aperture and <0.7 Angstrom bandwidth. With Feather-Touch focuser, advanced air-pressure tuning system, and B3400 Blocking Filter. The solar telescope for professionals!

This superlative solar telescope provides the highest level of performance ever in a serial produced H-alpha telescope!
A precision aligned refractor with 230mm free aperture without central obstruction, and 1610mm focal length, for solar observing in H-alpha wavelength. Utilizing advanced high-contrast coatings and the Doppler True Pressure Tuning system “Pressure Tuner” the solar observer will able to experience an un-paralleled level of visual and imaging performance at highest magnifications.
An internal Etalon with advanced air-pressure tuning system “Pressure-Tuner” provides <0.7 Angstrom bandwidth. This “Pressure Tuner” system allows a more accurate Etalon adjustment than other systems. The “Pressure-Tuner” system adapted the Etalon to varying altitudes and atmospheric pressures for always optimal performance. The Etalon is installed safely inside the telescope-tube.

NEW: Included is now also the microprocessor controlled Pressure-Tuner control system PC1 as standard!

Blocking-filter is the B3400. The B3400 is good for solar imaging. We recommend a additional 90° star diagonal for visual observing.
The straight extension tube in which the blocking filter is installed, is equipped as standard with a connection for 2" eyepieces and with a adapter for 1.25" eyepieces.
Fine adjustment is achieved by a Starlight-Instruments Feather-Touch focuser with 10:1 reduction.

• Advanced Narrow Band Hydrogen-alpha Dedicated System.
• A refractor based system with a 230mm front objective.
• An unobsructed internal HD Etalon with the NEW Pressure Tuner allows for <0.65 Angstrom bandwidth, providing slightly higher surface detail without the loss of edge detail.
• The system includes the moutning rings and dovetail, dust caps.

Technical data:

• Type: Single Interference HD Etalon
• Tuning: air-pressure tuning system
• Aperture: 230mm
• Focal Length: 1610mm
• Focal Ratio: F7
• Bandwidth: <0.7 Angstrom @ 656.28nm
• Focuser: Starlight Instrument 2.5" Feather Touch
• Two tube rings
• Dove tail bar with Losmandy level for astronomical mounts
• Length: 155cm
• Weight: 31kg

Delivered by order:

• LS230THa H-alpha solar telescope
• Pressure-Tuner system
• Microprocessor controlled Pressure-Tuner control system PC1
• B3400 blocking-filter in straight extension tube
• Feather-Touch focuser
• Tube rings with dove tail bar (Losmandy level)
• LUNT zoom eyepiece
• Instruction manual
• Mount, Tripod, eyepice and other optional accessories are NOT included!

PLEASE NOTE: There will be manufactured only a few pieces per year of this professional H-alpha telescope. Therefore, it could be that the delivery time is more than one year! Please contact our customer service for more details if you are interested.

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.