Takahashi TOA-130NS 5.1" f/7.7 Ortho-Apochromat Triplet Refractor OTA

This performance of this Takahashi 5.1" ED triplet refractor is too good to let it be called simply an apochromatic scope. Only the term ortho-apochromatic is accurate enough to describe its optical excellence.

This Takahashi TOA-130 refractor optical tube has: 

• 130mm f/7.7 Ortho-Apochromat triplet optics with dual ED elements 
• 2.7" rack and pinion focuser with 1.25" eyepiece adapter
• retractable dew shield
• 250mm of back focus for CCD and film imaging
• state-of-the-art optical performance, exceeding even fluorite scopes
• 5-year warranty

    The Takahashi TOA-130 refractor provides exceptionally high optical and mechanical quality for the serious observer who needs optics of reasonable portability. The TOA-130 is exceptional for observing and imaging within the solar system. Its images of subtle lunar and planetary details are sharp, with realistic and highly saturated color. They are free from chromatic aberration's violet haze of spurious color, thanks to the scope's ED triplet optics. The latest antireflection multicoatings and numerous knife-edge internal baffles assure the maximum image contrast possible. 

This 5.1" Takahashi has a large aperture and diffraction-free images that make it surprisingly good for much deep space observing, as well. Binary stars and globular star clusters are particularly well-resolved and vivid, with the contrasting colors of many binary systems showing nicely. The brighter nebulas and galaxies stand out against a very dark sky background. 

The TOA-130's f/7.7 focal ratio and 1000mm focal length is long enough, using a Takahashi 2.8mm ED eyepiece to provide 357x, for high magnification observations of the Moon and planets, yet it will also produce a huge 2.5° field at 20x, using a 2" Takahashi 50mm eyepiece.

This Telescope's Optical and Mechanical Systems . . .

• Apochromatic triplet ED refractor optics: 130mm (5.1") aperture, 1000mm focal length, f/7.7 Ortho-Apochromatic triplet lens using two FPL-53 ED (Extra-low Dispersion) glass elements flanking a crown glass element for pinpoint stars and images that are free from spurious color (chromatic aberration).

   

• Multicoated optics: Fully coated on all surfaces with multiple layers of antireflection materials for high light transmission and good contrast.

   

• Retractable dew shield: Slows the formation of dew on the lens to extend your undisturbed observing time. Also improves visual and photographic contrast by shielding the lens from off-axis ambient light (the neighbor's yard light, moonlight, etc.) For transport, the retractable lens shade keeps the overall length of the optical tube to a manageable 32" when it is retracted and the visual extension tube removed.

   

• Rack and pinion focuser: 2.7" focuser, with a 2" eyepiece/accessory holder that threads into the 2.7" focuser drawtube. A 1.25" compression ring eyepiece/star diagonal holder is also supplied. The non-marring soft nylon compression ring of the 1.25" eyepiece holder won't scratch the barrels of your accessories or star diagonal, as ordinary thumbscrews can. Dual focusing knobs provide precise image control with either hand. The large focus knobs are easy to operate, even while wearing gloves or mittens in cold weather.
  The 2.7" focuser yields a 40mm image circle for virtually unvignetted 35mm prime focus photography. For medium format camera use, the TOA-130 is also available in a 4" focuser version (#TOA-131) that provides a 92mm image circle. A large thumbscrew locks the focuser tube in place without image shift at the correct photographic focus.
  A useful photographic accessory would be the Takahashi #CAA102 camera angle adjuster, shown below. This attaches to the 2.7" focuser drawtube in place of the 2" eyepiece holder. It allows the photographic accessory train to be rotated to the most appropriate angle to frame the object being photographed (a landscape format, portrait, or any angle in between) without having to loosen the camera adapter and perhaps lose the correct focus. Once the camera is oriented correctly, a large knob on the side of the adjuster can be tightened to hold the camera in place during the exposure.

   

• Finderscope mounting point: No finderscope is supplied, but a flat boss with two mounting bolt holes is provided on the top of the focuser body for mounting an optional finderscope. The Takahashi 7x50mm 6.2° field finder and bracket shown below are recommended.

   

• Long back focus: Back focus is a very good 250mm, allowing the stacking of a wide variety of CCD cameras, color filter wheels, electric focusers, camera angle adjusters, and film cameras.

   

• Optional photographic accessories: Three accessories are available to provide a variety of image scales and sky coverage: a field flattener, a focal reducer, and an extender. The field flattener reduces the focal ratio slightly (to f/7.53) and gives pinpoint stars to the very edges of the 40mm (2.3°) image circle for virtually unvignetted 35mm images. The focal reducer effectively cuts the focal length to 750mm and the focal ratio to f/5.76. The photographic field is now 3.8°, spread over a 50mm image circle for totally non-vignetted 35mm photography. A 1.6x extender (which can also be used visually) effectively increases the focal length to 1600mm and the focal ratio to f/12.3. The photographic field is 1.4° with this extender in use. A variety of photographic coupling attachments and eyepiece projection photography adapters are also available.

   

• Mounting rings: No mounting rings are supplied for the 155mm diameter optical tube. Two options are available. One is the Takahashi tube holder (#130TH) shown below that is designed specifically for mounting the TOA-130 on a Takahashi EM-200 or larger equatorial mount. The second option is a pair of Parallax split mounting rings (#PFS152), also shown below, for mounting on a non-Takahashi mount, such as a Losmandy G-11.

The image above shows the scope with an optional 7 x 50mm finderscope. The feature image below shows the rear cell of the scope as supplied, without the optional finderscope.

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