Takahashi TOA-130NFB 5.1" Ortho-Apochromat Triplet Refractor OTA

This performance of this 4" focuser 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, both visually and for medium format and 35mm/large format CCD imaging.

This Takahashi refractor optical tube has: 

• 130mm f/7.7 Ortho-Apochromat ED triplet optics
• 4" rack and pinion focuser with 2" and 1.25" eyepiece adapters
• retractable dew shield
• camera angle adjuster
• 250mm of back focus for CCD and medium format film imaging
• state-of-the-art optical performance, exceeding even fluorite scopes
• 5-year warranty

    The Takahashi TOA-130NFB refractor provides exceptionally high optical and mechanical quality for the serious visual and photographic 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. Its 4" focuser permits medium format imaging of a huge 5.3° swath of the sky with pinpoint images when using an optional focal reducer.
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: .1" (130mm) aperture, 1000mm focal length, f/7.7 Ortho-Apochromatic triplet lens using an FPL-53 ED (Extra-low Dispersion) glass element between two crown glass elements for images that are free from spurious color (chromatic aberration). For more details, click on the "Takahashi triplet lens" icon above.
• 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: 4" focuser, with a 2" eyepiece/accessory holder that threads into the camera angle adjuster attached to the 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 4" focuser yields a 92mm image circle for medium format prime focus photography with a Mamiya 645 or Pentax 6x7 camera. Needless to say, the 92mm image circle also allows absolutely unvignetted imaging with 35mm film cameras and the new 35mm-size and larger CCD chips. A large thumbscrew locks the focuser tube in place without image shift at the correct photographic focus.
  The built-in camera angle adjuster 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, 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/7.68) and gives pinpoint stars to the very edges of the 92mm (5.3° field) image circle for unvignetted medium format (6x7cm) and 35mm images. The central 70mm of the field is fully illuminated, with a gradual falloff to 85% illumination at the edges of the field. 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.

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