This compact telescope enables solar observation in H-alpha light.
A front non-obscured (full aperture) Etalon filter creates a half-width of less than 0.75 Angstrom. Solar prominences and surface details can be safely observed this way. Thanks to its extremely compact design, it is an ideal travel companion. The diagonal mirror, with its inbuilt blocking filter, is equipped with a helical focuser for 1.25” eyepieces.
Key features:
- 50mm clear aperture with no central obstruction
- 350mm focal length
- Internal etalon with pressure tuning system: “PT Pressure Tuner”
- Half width < 0.75 angstrom
- Non-rotating helical focuser
- Tube clamps with 1/4-20 thread (standard tripod thread)
Two versions of this model are available: one with a B400 and one with the larger B600 blocking filter. The B600 version is shown above. However, the difference can only be seen on its label.
Double stacking with a half width reduction to <0.5 angstrom is also possible. Lunt Solar Systems have designed their new LS50C Double Stack filter in its compact housing for this purpose (look under “Recommended Accessories”). This filter can be directly screwed on to the LS50THa telescope and provides significantly more detail and contrast on the Sun's surface.
Regular LS50FHa and LS60FHa double stack filters can also be used on LS50THa telescopes. The LS150/50 adapter, also found under “Recommended Accessories”, is designed for this purpose.
PT pressure tuner: Fine-tuning on the Etalon filter is provided via an air pressure system. A small change to air pressure within a pressure chamber inside the telescope changes the refractive index of the air, resulting in precise yet effortless adjustment to the H-alpha spectral line. The pressure tuner guarantees a uniform image with no central obstructions and a long-lasting wear-resistant etalon.
It not only matters which telescope you buy but also where you buy it. Our additional services:
- We are a leading telescope dealer and know the devices we sell. Our customer service team will gladly help you after your purchase if you have problems with assembly or operation.
- We provide a copy of the 80-page "Telescope ABC" beginners handbook with every telescope.
Our expert comment:
Amongst Lunt telescopes, there are a number of versions with different features. The model which is on offer can be deduced from the label.
An important price-influencing feature is the blocking filter size. There are 4 different blocking filters, with diameters of 4mm, 6mm, 12mm and 18mm. These are known as the B400, B600, B1200 and B1800. Unless otherwise stated in its name, an OTA does not include a blocking filter.
CaK or Ha indicate whether the devices are optimised for blue calcium spectral lines or for red H-alpha spectral lines. Over 90% of devices on sale are H-alpha devices, designated with Ha.
C or FT are used to distinguish between two versions of focusers. C is for standard focusers. FT is an improved model produced by FeatherTouch.
PT denotes devices with air pressure fine-tuning. Filters without PT use tilting for fine-tuning. Generally, air pressure models provide a more homogenous image field.
DS or DS50 are the identifiers for double stack. These devices have 2 etalon filters. These create narrower bandwidths and improved contrast.
2 numbers separated by a slash can also be found in the name. The first number denotes the diameter of the front lens. The second number is the focal length. So, a 60/500 is a telescope with an aperture of 60mm and a focal length of 500mm. Lens diameter generally refers to the diameter of the provided etalon.
(Bernd Gährken)
