About the Istar 140mm (5.5") f/12 Super Apochromatic Lanthanum Lens & Cell Only...
Istar''s mechanical and optical designs are created in the Czech Republic, Europe. All Istar Lens and Cells are designed by Master Optician Zdenek. The Istar Optical Refractor Telescopes and related parts were designed by the owner of Istar, Ales Krivanek. Telescope tubes and dew shields are produced in Austria and CNC machined and powder coated in the Czech Republic. Istar Optical Refractor Telescopes are assembled by hand and tested in the Czech Republic and the United States. Currently all materials used are of European origin with the exception of focusers that are made in the US. A major expansion will take place in 2012 with most manufacturing and assembly being moved to the United States. Istar Optical Refractor Telescope Lens and Cells are ground and polished in Asia to Istar''s exact quality specifications and exported to the US to be mounted and shipped worldwide. Only brand name glass from O''Hara, Schott and CDGM is used.
Istar Lens and Cells are made to meet high quality standards. Many knowledgeable and experienced astronomers have made it clear that even though these Istar Optical Refractor Telescopes have only a modified Fraunhofer (air spaced achromatic doublet) in them, they are suitable for a good quality Moon, planetary and DSO photography. Incredible results with pinpoint starts and vivid colors have been achieved with use of a narrowband filter.
There are many manufacturers offering so called Fluoro-Star, Fluoro-Triplet and Fluorite Triplet Glass to make buyers believe their instrument is made with a pure fluorite element. Calcium Fluorite is the best optical material on the market today in terms of color correction. It is also the most expensive. All lens designated CF are made with pure crystallized Calcium Fluorite, CaF2. There are very few manufacturers that produce telescopes made with this rare material. Images taken with CaF2 triplets are in class by themselves and are rightfully considered to be the very best among knowledgeable astrophotographers.
Istar 140mm (5.5") f/12 Super Apochromatic Lanthanum Lens & Cell Only Features...
- Special exotic glass types to achieve 30 to 60 percent reduction in CA and spot size compared to a common doublet
- Istar Lens and Cells are made to meet high quality standards
- Lenses are ground and polished in Asia to Istar''s exact quality specifications
- Only brand name glass from O''Hara, Schott and CDGM is used
- All lenses designed by Master Optician Zdenek
Istar 140mm (5.5") f/12 Super Apochromatic Lanthanum Lens & Cell Only Specifications...
Item description: Lanthanum Super Apochromatic Hand Figured Lens in Push-Pull Style Cell
Lens Diameter: 144mm
Clear Aperture: 140mm
N of elements: 3
Focal length: 1680mm
Type Coating: Broadband Multilayer Film (Green Yellow)
Fully Multicoated: yes
Average Strehl Ratio: 0.95
Weight (Incl. Cell): 4.10 Kg
Cell O. Diameter: N/A
Handfigured: yesIstar Product Number: ISSAPOLENS140-12-LAN