The 130mm f8 StarFire EDT is a very portable, lightweight refractor with a Super ED triplet objective that is highly corrected for false color (chromatic aberration). The color error is lese than 0.01% from 706nm to 450 nm, compared to a two element Fluorite apochromat with 0.05%, or a Doublet Achromat with 0.45% color error over the same spectral range. In an age when Fluorite is being marketed as the best lens material for fast refractors, it is significant that Astro-Physics has developed a non-Fluorite objective with 5 times better chromatic aberration at a fraction of the cost of Fluorite. Super ED glass (ED stands for extra low dispersion, Vd> 90) is a real glass, not a crystal like Fluorite. ED is a harder, less fragile material with a much lower expansion coefficient than Fluorite. Unlike Fluorite, ED glass is not affected by atmospheric contaminants and acids. It is for these reasons that all the world's major camera manufacturers are incorporating ED glass into their best lenses.

The extremely high color correction of the Super EDT design allows the construction of a relatively short-focus objective that is superior to long-focus achromats in contrast and definition of subtle planetary detail. The EDT lens is also perfectly matched to the characteristics of the fine grained Technical Pan emulsions which have their peak sensitivity at 45nm. With our matching accessories, you can create impressive astrophotos with CCD cameras, or on 35mm and 6 x 7cm film formats.

The optical design of the 130mm EDT objective consists of a positive element of ED glass surrounded by two matching hard crown meniscus lenses. The two outer elements are chosen so that the combination is free of coma, spherical aberration and other higher-order aberrations. All surfaces are spherical, which results in a very smooth overall figure. Under steady viewing conditions, you will see a hard white Airy disc at focus surrounded by the first diffraction ring. Inside and outside of focus, you will see an evenly illuminated, expanded disc with concentric Fresnel rings, the outermost ring brighter and wider than the rest. The two air-glass surfaces have multi-layer anti-reflection coatings that result in overall light transmission greater than 97% in peak visual wavelengths.

Our superb Astro-Physics focuser is a very finely crafted unit with several unique features. The components are machined on Astro-Physics' CNC to extremely high tolerances, assuring that there is no wiggle between the drawtube and housing. More than a dozen knife-edge baffles are machined into the wall of the drawtube and painted flat black in order to maximize contrast by essentially eliminating any internal reflections. We inside diameter (I.D.) of the drawtube is 2.7" which allows the avid astrophotographer to use a medium format camera to capture images in a 6 x 7cm format with minimal vignetting. You can use standard accessories with the 2" and 1.25" adapters. Recessed brass locking rings are installed at each thumbscrew location. As you tighten each thumbscrew, the brass locking ring damps onto the part that has been inserted. Consequently, your focuser drawtube and 2" and 1.25" accessories are held securely in place. This is particularly important considering the heavy and expensive accessories that you may use. As an added advantage, the brass will not mar the surface of your accessories.

The 130EDT optical design is ideal for astrophotography with small- and medium-format cameras. The widefield coverage in the 6x7 photographic format will record gorgeous images of a wide variety of objects such as the Andromeda Galaxy and the Lagoon and Trifid Nebulas. The negatives contain so much finely resolved detail that you can enlarge a small portion to feature one particular aspect of the object, i.e. the Gulf of Mexico portion of the North American Nebula. One of the finest solar eclipse photographs of the corona was taken with the 130 EDT StarFire refractor in July 1991. This photo and other deep sky photos that were taken with our 5" f8 StarFire have appeared on the cover of numerous astronomical publications around the world.

Diagonals and Binocular Viewers: Prism diagonals have aberrations which degrade image quality. Since this is especially noticeable in telescopes with fast focal ratios, we recommend the 2" Precision Mirror Diagonal. If you use a binocular viewer (which has prisms), then place a Barlow between the focuser and binocular viewer.

Eyepieces: Plossls, Orthoscopics, and Widefield eyepieces show sharp images only in the center of the field. These are fine as long as you realize this limitation. If you object to astigmatic images at the edge of the field, we recommend the TeleVue Nagler and Panoptic eyepieces. These oculars have the best flat field images and will bring out the most in your 130 StarFire EDT. Use our 2x (2") Barlow to double your magnification.

Right: Company Seven ATA Case custom fitted for a Astro-Physics 13cm EDT Apochromat Telescope with 2.7 inch Focuser (65,974 bytes). Click on image to see enlarged view (215,942 bytes).

Features include:

Left: Astro-Physics Model 900 Mount in optional Company Seven ATA case. Case 1 of 2 shown here, with Declination housing (left side shown) with GTO Keypad Controller and Counterweight Shaft (94,326 bytes).

Please refer to the brochure for descriptions of these items and additional accessories.

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Company Seven | Astro-Physics 13cm f8 EDT Telescope