This 100mm Sky-Watcher Evostar 100ED doublet apochromatic refractor is a premium scope with high contrast/high resolution performance and premium accessories at a very attractive price . . .
This Sky-Watcher Evostar 100ED apochromatic refractor has:
• 100mm f/9 apochromatic doublet optics using an ED element
• dual-speed 2" Crayford focuser with 10:1 ratio fine focusing
• 2" dielectric star diagonal with 2" and 1.25" eyepiece holders
• two 1.25" eyepieces (25mm and 5mm)
• 8 x 50mm right-angle finderscope
• dovetail shoe for installing on a Celestron CG-5 mount or any Vixen-style altazimuth or German equatorial mount
• two-year warranty
The Sky-Watcher Evostar 100ED uses a crown glass element, an ED glass element, and state-of-the-art optical multicoatings in its apochromatic ED doublet optics. Combined with the moderate focal ratio, this results in images with visibly less chromatic aberration than you find in refractors with a similar aperture but faster focal ratio. In addition to the lack of chromatic aberration's annoying halo of unfocused violet light around bright stars and solar system objects, there is no loss in contrast such as you will find in reflector and catadioptric scopes that have a secondary or diagonal mirror hanging in the light path to scatter light..
The 100mm Sky-Watcher doublet optics are even more appealing when you consider that this Sky-Watcher apo is loaded with features other manufacturers charge extra for (or don't even have available) - such as an 8 x 50mm right-angle finderscope, a 2" dielectric star diagonal with 1.25" and 2" compression ring accessory holders, two 1.25" eyepieces (25mm and 5mm); and a foam-lined aluminum-clad carrying case.
The Sky-Watcher PRO 100ED has enough premium high contrast/high resolution optical performance to let you use it on an altazimuth or equatorial mount as the heart of your observing system. Its light weight (only 6.6 pounds) doesn't require a big and expensive mount, so it's easy to afford and easy to take out and set up for observing on a moment's notice. Considering its surprisingly low price for an apochromatic doublet, adding in the extra features you get at no extra cost, and in view of the great optical performance that comes as standard equipment, the 100mm Sky-Watcher PRO 100ED is a terrific buy!
Features of this telescope . . .
Apochromatic ED doublet refractor optics: 100mm (3.94") aperture, 900mm focal length, f/9 focal ratio. The ED element is precision-polished from high grade ED (Extra-low Dispersion) glass. This ED element produces superior sharpness and color correction by minimizing the chromatic aberration, the "false" color fringing seen around bright objects when light rays pass through standard crown-and-flint doublet objectives. The result is to reduce spurious color halos and fringing to vanishingly low levels.
Fully multicoated optics: Each air-to-glass surface in the Sky-Watcher Evostar 100ED doublet objective lens has MHC (Metallic High-Transmission Coating) antireflection multicoatings on all air-to-glass surfaces for high light transmission, minimal light scatter, and excellent contrast.
Internal light baffles: Contrast-enhancing internal light baffles in the tube and focuser drawtube and a specially darkened tube interior provide dark sky backgrounds and high terrestrial contrast.
Dew shield: The supplied dew shield slows the formation of dew on the lens in cold weather to extend your undisturbed observing time. It also improves the contrast, similar to the effect of the lens shade on a camera lens, when observing during the day or when there is excessive ambient light at night, such as a neighbor's backyard security light. The 6.6 pound optical tube measures 36.22" long, including the dew shield. A slip-on metal dust cap is standard.
Dual speed 2" Crayford focuser: The precision-made no-backlash focuser has dual-speed focusing. There are two coarse focusing knobs. The right knob also has a smaller concentric knob with 10:1 reduction gear microfine focusing. This provides exceptionally precise image control during high magnification visual observing and critical imaging. The large focus knobs have ribbed gripping surfaces so they are easy to operate, even while wearing gloves or mittens in cold weather. Lock knobs lets you adjust the tension on the drawtube to accommodate varying eyepiece/photo accessory loads, as well as firmly lock in a photographic focus.
2" dielectric star diagonal: The supplied standard equipment 2" mirror star diagonal of the Evostar 100ED slips into the focuser drawtube's 2" eyepiece/accessory holder. The 2" diagonal has 99% reflectivity dielectric mirror coatings for high light transmission. A supplied 1.25" accessory adapter slips into the 2" diagonal to let you also use 1.25" eyepieces. The 1.25" accessory adapter can also be inserted directly into the 2" accessory holder on the focuser drawtube to let you use a 1.25" image erecting diagonal, or 1.25" photographic accessories.
Supplied eyepieces: Two 1.25" eyepieces are supplied as standard equipment - a 25mm (36x) and a 5mm (180x).
Finderscope: The Sky-Watcher Evostar 100ED comes with an 8 x 50mm right-angle finderscope that is fully-multicoated to insure maximum brightness and contrast.
Mounting dovetail: The Sky-Watcher Evostar100ED apo from Celestron has dual hinged split-ring tube rings and a dovetail mounting bar that fits directly into the Vixen-style dovetail slot on the head of many of the most popular medium capacity altazimuth and German equatorial mounts. Such mounts include the Astro-Tech Voyager II altazimuth and the Celestron AVX Advanced Series go-to equatorial, among others.
Shipping/storage case: The scope comes in foam-fitted aluminum-clad shipping/storage case.
Two-year warranty: The Sky-Watcher Evostar 100ED doublet apo is protected by a two-year limited warranty against flaws in materials and workmanship.
