ASA Astrograph 20" N-series
Are you a first time astrophotographer and can’t decide which astrograph is best, portable, fits your budget etc? AstroSysteme Austria, commonly known as ASA, has quite the surprise and resources for you to assist in your choice. Their 20" Astrograph is portable and weighs 20 pounds, so initially you’d probably think it lacks those high end astrophotography optics that its competitors may have. Guess what, you’re dead wrong!
The 20" ASA astrograph can be used with a wide variety of accessories. Among some of the best are correctors which can fluctuate the telescope’s focal length. This astrograph has a focal length of 720mm, but can vary depending on the type of corrector you decide to use. For instance, let us suggest the observer uses the ASA 3” Wynne corrector in conjunction, the original focal length is reduced by a factor of 0.95. Therefore, the astrograph’s focal length can be shortened 0.73 or expanded by 1.8. This is the primary difference of what sets this telescope apart from its brothers, its startling corrector accessory compatibility. Astrophotographers couldn’t be happier!
Taking a step out for a second, it becomes clear that ASA knows its astrographs must be simpler with meeting the eye. Of course accessory compatibility is fantastic, but the overall design of the astrograph is important as well. What makes this item so lightweight, portable and attractive? The optical tube of the 20" ASA astrograph is composed of carbon fibre and is covered with velvet for avoidance of stray light. These materials are very lightweight.
Astrograph’s with quick focal ratios tend to excel better with accurate short exposure times. This results in good signal to noise ratio and therefore provides more satisfying results to the user. The 20" Astrograph by ASA has just this. This optical design is based upon Dipl. Phys. Philipp Keller in Germany.
|Name||ASA - Astrograph 20" f/3.6|
|Manufacturer||ASA - Astrosysteme Austria|
|Focal Length||1900 mm|
|Image circle||50 mm|
|Optical Design||Newtonian Astrograph|