Lightweight Dobson Telescopes And High Quality Parabolic Mirrors - Made in Germany!
For a few months only: reduced prices for the Infinity NL model series
16" Dobsonian Telescope "Infinity NL": Optics
Silver-white shining clouds on the mountainsides of Martian vulcanos, finest details in colorful planetary nebulae, singular stars within the densly
packed centers of globular clusters or the slim jet of the Messier 87 black hole - to observe these things successfully not only a large telescope
aperture is needed but high quality optics are also essential.
This is why the core of all „Infinity NL“ telescopes is an optical system of very high quality which not only refers to the primary but also the secondary
mirror. This combination will fascinate you with sharp high contrast images and show you countless wonderful details that will surprise you time and
again.
1) The Primary Mirror
Every primary mirror within an „Infinity NL“ telescope is made in Germany within the facilities of Spacewalk Telescopes. The high quality blank disk
made by "Schott" is carefully ground, polished and given its parabolic form there, creating a precise and unique mirror for your telescope.
During the whole manufacturing process the optical quality of the mirror is constantly monitored. This includes inspections of the surface quality during
grinding and polishing processes as well as several interfeometrical analyses of the parabola when giving the mirror the desired parabolic shape. Especially
the final measurement is of great importance since this is where the information about the quality of the finished product is determined. This is why a lot of
effort is put into the measurement, averaging many interferograms to define the Strehl-ratio and therefore the performance capability of the mirror as
precisely as possible.
You will receive an intererometric test protocol including all information an a specific description of your unique mirror in print.
The primary mirror is declared finished when the Strehl-ratio measured by "Spacewalk Telescopes" is at least S=0.90 .
Another important and often neglected aspect of a primary mirror is its edge thickness. The Spacewalk Telescope primaries have an edge thickness of 25mm and therefore qualifies
as very thin. As a result they cool down incredibly fast, giving you the opportunity to use even high magnifications already after a very short time.
After all why waisting precious observing time?