Explore Scientific - Generation II - 20-inch Truss Tube Dobsonian Telescope - SKU# DOB2036-00
THIS PRODUCT REQUIRES A 90-DAY LEAD TIME FROM ORDER TO SHIPPING. THERE ARE ADDITIONAL CUSTOM DELIVERY CHARGES (WHETHER OR NOT ASTROZAP HAS ANY PRODUCT OR SHIPPING DISCOUNTS RUNNING AT THE TIME OF PURCHASE) THAT WILL BE DUE AT TIME OF SHIPPING. IN THE U.S. THIS CHARGE CAN BE $600 OR MORE. ASTROZAP WILL CONFIRM YOUR TOTAL SHIPPING CHARGE WITH YOU BEFORE WE PLACE THE ORDER WITH EXPLORE SCIENTIFIC.
The ideal workhorse for the deep sky observers, the Explore Scientific 20-inch f/3.6 Truss-Tube Dobsonian is our largest aperture telescope. The 500mm mirror collects 5100 times more light than the naked eye. Details on planets and deep sky objects will be visible even for inexperienced observers. Bright star clusters are resolved to the core, and the sight of the terminator on the moon is an unforgettable experience.
The fast 20" f3.6 main mirror as well as the large 120mm secondary mirror are made of high quality quartz material, so the cooling time is reduced to a minimum and this Dobsonian is quickly ready for use. Every main mirror is delivered with an individual optical test certificate, which guarantees the highest capacity. A laser engraved center mark of the main mirror allows easy adjustment. The optical surface has a high-quality aluminum coating with 94% reflectivity and an extremely resistant quartz protection layer. The mirror overcomes frequently occurring dew fogging and cleanups without damage and guarantees a long service life.
A complete redesign of this Dobsonian was necessary to ensure the significantly increased requirements to stiffness and load bearing capacity of the optical components. All connections of the tube structure were made in the TIG welding process and no rivets and screws were used. This has made it possible for us to produce this 20" light weight Dobsonian so unbelievably stiff in spite of the low weight - a noticeably good quality which is begging you to take one home.
A second 40° displaced installed mounting plate with a viewfinder shoe allows the rotation of the tube top in combination for a favorable position of the viewfinder tube or the mounting of an additional TELRAD viewfinder. The 6 supporting feet underneath the rocker box offers perfect stability and guarantees smooth tracking in azimuth. Four smaller fans are installed in the side of the mirror box as well as a large fan installed under the main mirror. This allows an even quicker adaptation to the ambient temperature and reduces the tube seeing (boundary layer removal). The lateral altitude wheels can now be stowed comfortably in the foam layers of the mirror box.
Includes 2.5" HEX focuser with helical gearing and 10:1 reduction; LED Red Dot Finder, collimation assist tool; soft light baffle and two radial main mirror fans for fast temperature equilibrium.
The scope is ready for the use with our optional coma corrector.
|Focal length||1,826 mm|
|Primary mirror diameter||50 cm|
|Mirror cell support points||18|
|Truss pole length||100 cm|
|Truss pole diameter||25 mm|
|Secondary cage assembly diameter||57 cm|
|Secondary cage assembly weight||8 pounds|
|Secondary cage assembly height||95 cm|
|Mirror box/rocker box height||56 cm|
|Mirror box weight *||105 pounds|
|Height to center of eyepiece at zenith||170 cm|
|Theoretical limiting stellar magnitude||0.23 arc sec|
|Theoretical Rayleigh limit||0.23 arc sec|
|Theoretical limiting magnitude||16.19 mag|
|Theoretical maximum magnification||1,000x|
|*||Mirror weight can vary because of the manufacturing process; these values are approximate|