The EvoStar 100mm f/9 Doublet APO Refractor from Sky-Watcher features a doublet apochromatic lens system with Extra-low Dispersion (ED) glass and Sky-Watcher's proprietary photon anti-rejection Metallic High-Transmission Coatings (MHC) on all air-to-glass optical surfaces. This combination of glass, lenses, and coatings virtually eliminates chromatic aberrations for clear and bright high-contrast images with true color rendition. This is a versatile optical tube assembly (OTA) that is well suited for wide-field astronomical observation of prominent nebulae, star clusters and galaxies, or can be used as an astrograph for sky photography, a terrestrial spotting scope or telephoto lens. The aperture of this 100mm model of the ProED not only increases image brightness over the smaller 80mm version, it improves resolution and contrast.
A mounting cradle-ring clamps over OTA and allows the user to adjust the orientation and position of the scope relative to the mount to optimize viewing comfort and balance, while avoiding interference with other equipment. The scope is offered without a mount or tripod, but a Vixen-style dovetail plate makes it compatible with any alt-az or equatorial mount with a Vixen-style saddle.
Its two-speed Crayford-style focuser helps make fine-focusing fast and precise without backlash. The EvoStar comes with several accessories to help you get observing faster and easier. First, are two long eye relief eyepieces that produce 30 and 120x magnification, a 90° star diagonal for more comfortable viewing, and a large 8x50 erect-image finderscope to make finding your celestial objects faster and easier. Finally, Sky-Watcher provides a foam-lined aluminum carrying case to safely store and transport the OTA.
- 100mm objective lens
- 900mm focal length
- Focal ratio: f/9
- Refractor-style optical design
- Extra-low Dispersion (ED) glass
- Apochromatic doublet lenses eliminate chromatic aberrations for true color rendition and enhanced contrast
- Proprietary anti-reflection Metallic High-Transmission Coatings (MHC) multi-coatings on all optics
- Objective lens cell is light-baffled to reject stray, unfocused light
- Baffled draw tube for enhanced contrast
- OTA interior is flat blackened to help prevent unfocused internal light reflections from reaching the focal plane
- Resolution, Rayleigh: 1.39 arcsec
- Resolution, Dawes: 1.16 arcsec
- 2" diameter focuser
- Dual-speed Crayford-style
- Crayford focusers use a toothless friction system that allows for super-fine precision focusing without backlash
- Includes 1.25" adapter for using smaller eyepieces and accessories
- Two 1.25" barrel diameter eyepieces:
- 5mm eyepiece: Yields 180x magnification
- 20mm eyepiece: Yields 45x magnification
- Diagonal:
- 90° angle
- Dielectric coatings for greater than 99% reflectivity
- Star diagonal corrects images vertically, but not horizontally
- 8x50 erect-image finderscope with bracket
- Foam-lined hard aluminum carrying case
- User-supplied mount and tripod required
- Vixen-style dovetail plate included
- Compatible with any alt-az or equatorial mount with a Vixen-style saddle
- Cradle-ring assembly for plate allows the scope orientation to be changed based on mount configuration
- Integrated 1/4"-20 piggy-back camera mount for wide-field astrophotography
- Quick-release system for fast setup and breakdown