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telescopes

Philotes APT 172-8 Apochromatic Refractor Telescope OTA [ISAPT172-8]

Istar Optical   ——   SKU: ISAPT172-8
$5,895.00 CAD
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About the Istar Philotes APT 172-8 Apochromatic Refractor Telescope OTA...

Ask anybody to describe a telescope and the image of a long tube and lens at the end will be their answer. Except for the diagonal, which makes possible viewing at a comfortable angle, there are no mirrors to scatter and lose light. There is no central obstruction with the Istar Philotes APT 172-8 Apochromatic Refractor Telescope, no frequent collimation to worry about and very reasonable cool down time. How about sharp, high contrast views of the Moon and planets? If you like black velvety backgrounds with pin point stars, a Istar Optical Refractor Telescope is for you.

 

Using long focal lengths puts large aperture Istar Optical Refractor Telescopes within reach of most amateurs. Most people associate inexpensive achromatic lenses with horrendous amounts of false color (chromatic aberration). Not so with longer focal lengths like the Istar Philotes APT 172-8 Apochromatic Refractor Telescope. When the focal length is increased in relation to the aperture the inherent aberrations associated with achromats are minimized. Another advantage is depth of focus. No constantly tweaking the focus on this Istar Optical Refractor Telescope. Greater depth of focus allows a steady, comfortable viewing experience especially when observing the Moon, planets and double stars.

 

Istar does not offer mass produced telescopes with non-replaceable focusers, low quality rings and dovetails. Instead, we offer you the option to purchase a bare OTA like the Istar Philotes APT 172-8 Apochromatic Refractor Telescope with optics and give you a choice of focusers, mounting rings and dovetail. You do not have to purchase these from Istar. You are welcome to buy from third party manufacturers. However, we offer the original Istar PRO style rings and dovetails that are of the highest quality, stability and match each Istar Optical Refractor Telescope perfectly.

 

Istar uses special exotic glass types to achieve 30 to 60 percent reduction in CA and spot size compared to a common doublet made with popular less expensive glass types. Istar ships all Istar Optical Refractor Telescope like the Istar Philotes APT 172-8 Apochromatic Refractor Telescope with a specially designed lens cap. You can decrease or increase friction inside of the dew shield by loosening or tightening the two silver bolts. When you tighten them the diameter of the foam ring will increase therefore increasing the friction inside the Istar Optical Refractor Telescope dew shield. They look unlike any other lens cap on the market and of course and they work better than any other lens cap.

 

Istar Optical Refractor Telescopes like the Istar Philotes APT 172-8 Apochromatic Refractor Telescope are built around "color scheme" which is not just aesthetically attractive but highly functional. Achromats are black matte with a polished silver counter cell and silver back plate. Apochromats are black matte with a red-gold counter cell and red-gold back plate. Add a set of black CNC machined rings, black focuser and black Istar diagonal with polished silver body plate and you have a beautiful Istar Optical Refractor Telescope. The textured finish is not only durable but gives a sure grip when handling the tube. Black does not require any longer cool down time than the popular white tube. However, if you do not like black, white is available for a small additional charge.

 

Istar'''s mechanical and optical designs are created in the Czech Republic, Europe. All of their Istar Optical Refractor Telescope Lenses were 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 such as the ones employed by the Istar Philotes APT 172-8 Apochromatic Refractor Telescope 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 Lenses 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 Optical Refractor Telescope Lenses used in the Istar Philotes APT 172-8 Apochromatic Refractor Telescope 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 telescope 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 Istar CFT Optical Refractor Telescopes are made with pure crystallized Calcium Fluorite, CaF2. There are very few manufacturers that produce scopes 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. Have you viewed a DSO or planetary image taken with a Istar Philotes APT 172-8 Apochromatic Refractor Telescope? If you did, you are probably saving your money to purchase one!

 

Don''t forget... We carry essential Istar Optical Refractor Telescope Lens and Cell assemblies, as well as Istar Optical Telescope Accessories!

 

 

Istar Philotes APT 172-8 Apochromatic Refractor Telescope Features...

 

  • Special exotic glass types to achieve 30 to 60 percent reduction in CA and spot size compared to a common doublet

     

  • Decrease or increase friction inside of the dew shield by loosening or tightening the two silver bolts

     

  • 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

     

  • Textured finish is not only durable but gives a sure grip when handling the tube

 

 

Istar Philotes APT 172-8 Apochromatic Refractor Telescope OTA Specifications...

Type: Apochromatic

Number of elements: 3

Lens Diameter: 177mm

Clear Aperture: 172mm (6.7 inches)

Focal Length: 1415mm

F-Stop: F/8

Lens Coating: Fully Multi-coated

OTA weight:N/A

OTA Length:N/A

Istar Product Number: ISAPT172-8

 

Customer Note: Images depict optional accessories. This is an optical tube only.