Tecnosky presents the giant of the OWL series, an SLD apochromatic refractor with an impressive diameter of 180 mm and a focal length of 1260 mm! It is a top-of-the-range apochromatic triplet refractor, as it uses two FCD100 lenses from the Japanese company Hoya – a guarantee for images free of any chromatic aberration! All lenses are also fully multi-coated (FMC) on every optical surface. In addition to the use of excellent glass, the optical processing of the lenses is equally important: this refractor has an individual optical interferometric certificate with a Strehl ratio of at least 0.95. In order to hold such large and heavy lenses, the cell is made of CNC-milled Ergal, which, due to its physical properties, does not allow bending or expansion. The lens cell is also collimated so that it can be aligned precisely with the focuser.
The tube is made entirely of aluminium with internal baffles and a long, retractable dew shield. The sturdy tube clamps have a 330 mm long, wide Losmandy rail for mounting and a practical carrying handle on top. The huge 4" focuser with 1:10 fine reduction is designed for astrophotography at the highest level - even with heavy cameras equipped with filter wheels or off-axis guiders. The clear aperture of no less than 105mm is necessary to illuminate the field with its 4" focuser.
Between the tube and the focuser there is an extendable extension that moves on three linear guides, allowing a back focus of 95 mm to be achieved. This is ideal for use with binocular heads or special flatteners.
A 180 mm apochromatic refractor is a dream for every astronomer, because the lack of obstruction provides incredibly detailed and high-contrast images of the Moon, planets and double stars that are difficult to achieve with mirror telescopes. In the deep sky, such a refractor competes with much larger instruments due to its high light concentration and optical quality. Deep sky objects appear almost three-dimensional with stars as small as pinheads. In combination with a 0.8x reducer, it becomes a very fast f/5.6 Astrograph with a focal length of 1008 mm, but with the detail, sharpness and contrast of a 180 mm triplet.
