Probably the best telescope available for imaging the sun in Hydrogen Alpha light due to the enormous aperture of 6", a 900 mm focal length, 100% unobstructed aperture for high contrast, and a bandwidth of <0.65 Angstroms.
The Lunt 152mm H-Alpha Solar Telescope is a very useful addition to any school or university observatory, or for amateur images who want to capture some of the best images possible, period. Visually this telescope is an absolute delight too, and we recommend the Altair Lightwave Long Eye Relief eyepiece range as a great accessory for any solar telescope. At starparties or public observing events, a 6" Solar telescope is probably the biggest crowd pleaser of all time!
Surface detail and prominences are easily visible and are hihgly dynamic, changing as you watch. It is safe to say the Lunt 152mm solar telescope can provide some of the best visual detail possible from the earth before you entering the realm of custom-made instruments (please enquire for details).
The 152mm OTA is packaged with a Blocking Filter of your choice as part of the diagonal mirror assembly. The wavelength of light is selected using a built-in pressure tuner system, which is an extremely accurate and convenient method for tuning, without the need for electronics, or mechanical tilt.*
We recommend the larger BF3400 filter for imaging with a DSLR or large-chip CCD camera because it reduces vignetting (darkening) at the edges of the field.
The BF1800 filter is compatible with most CCD cameras under APS size, and the BF1200 is more suited to cameras with smaller chips, visual observation, and of course the new wave of super high speed video cameras such as the iNova CCD/CMOS range.
Accessories include an additional Calcium-K module (LS152TCaKMD, product code 0551590). This can replace the standard H-alpha module in a few steps, so you can observe and image the sun with only one telescope alternatively in H-alpha light or in the Ca-K wavelength to reveal incredible structure in the sun's surface.
The Lunt 152mm H-alpha Telescope with internal Etalon and 152mm Aperture filter package includes:
Pressure Tuner system.
Your choise of blocking filter in star-diagonal (select from the product options menu).
Starlight Instruments 2" Feather Touch focuser.
Tube Rings with dovetail.
Scope carry handle.
* Having said that, a new plug-in digital electronic air pressure tuning system is now available, for those who require the same wavelength over repeated observations over time, where the natural air pressure changes with the weather. This is suitable for scientific research and for hobbyists who want to document the ever changing sun in a very scientific manner. Please enquire for more info.
More about the Lunt Pressure Tuner System:
The air pressure of the atmosphere varies, depending on if you are at sea level or on a mountain. Unfortunately all sensitive Etalon filter systems respond to these small changes in air density caused by natural air pressure variations, weather, etc.
The wavelength range passed through the HQ filter shifts as the air pressure changes. This shifting is indeed minimal, but at bandwidths of less than one Angstrom it is visible. If the filter is not adjusted precisely to the H-alpha wavelength, the image of the sun through the telescope degrades, and prominences and surface details become less visible.
Therefore, the Etalon filter systems have to be adjusted to the prevailing air pressure at their 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 artefacts such as a band of clarity passing over the sun's surface, often referred to by solar observers as the "Sweet Spot" which moves slightly as the mechanical etalon is tuned. This isn't necessarily a bad thing and it's less visble on smaller aprtures, but there are now systems which avoid these issues all-together.
The new air-pressure system “Pressure Tuner” by Lunt Solar Systems is a new design. The Etalon filter is not tilted to only simulate a change to the air pressure, but the air pressure in the filter system is in fact adapted to 100 percent of the real external air pressure. Therefore 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 incoming light waves, and instead of tilting, the system changes the refractive index of the air in the chamber instead. This accomplishes the same tuning effect except that variation is constrained to around + or - 0.4 Angstroms to either side of the centre tolerance. 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.