Sky-Watcher Evostar 100 ED OTAW Black Diamond tube (SW-2009)

This refractor is the larger sibling of the popular ED 80 model. It features a larger 100 mm aperture lens and a focal length of 900 mm. Like its smaller counterpart, the ED 100 is a favorite among astrophotographers. The combination of high-quality optics and a reliable focuser, along with maintaining a relatively lightweight design for this class of equipment, makes it ideal for astrophotography. For enhanced astrophotographic performance, a focal reducer (x0.85) can be added, delivering a corrected field of view with a focal length of 765 mm and an aperture of f/7.65.

Optical System

This refractor is equipped with a low-dispersion ED (FPL-53) doublet lens, ensuring excellent image quality with minimal chromatic aberration. This design excels in planetary and lunar observations, offering sharp views even at high magnifications, as well as in astrophotography. Apochromatic optics focus nearly all visible wavelengths at a single point, correcting chromatic aberration in the primary colors (red, green, blue) and eliminating spherical aberration in red and blue light. This telescope gathers approximately 210 times more light than the human eye, enabling observations of celestial objects with magnitudes up to 12.0 (compared to the naked eye's limit of 6.0). The 100 mm lens also provides optical resolution capable of separating stars spaced 1.4 arcseconds apart.

Accessories include a 90-degree dielectric diagonal with a 2-inch format and 98% optical efficiency. The kit also contains a 28 mm LET eyepiece (2-inch).

Focuser and Mounting

The refractor features a precise Crayford focuser with micro-adjustments, supporting both 2-inch and 1.25-inch eyepieces. It is sold without a mount, allowing users to pair it with their preferred setup.

Astronomical Observations

• Solar System: Observe lunar surface features larger than 1–1.5 km, sunspots and their structure, all Solar System planets, phases of Mercury and Venus, Mars' small disk, Jupiter’s equatorial bands and Galilean moons, Saturn’s rings and Titan, Uranus and Neptune as star-like points, asteroid motion against the stars, and bright comets.
• Stars: Observe approximately 1.1 million stars up to magnitude 12, double and multiple stars separated by over 1.4 arcseconds, and the colors of the brightest stars.
• Nebulae and Star Clusters: Nearly all objects in the Messier catalog, hundreds of globular and open clusters, brighter nebulae, and galaxies are visible.

Terrestrial Observations

This optical system also excels in terrestrial observation. When paired with a prism diagonal, the telescope functions as a high-quality spotting scope, offering detailed views and photography capabilities with its focal length.

Included Equipment

• 2" dielectric diagonal with a 90° angle and 1.25" adapter
• Tube rings, one with Piggyback mount
• 28 mm 2" eyepiece
• 9x50 finder scope
• Dovetail bar
• Carrying case

Specifications

• Catalog Number: SW-2009
• Optical Design: Refractor
• Lens Material: ED Glass
• Mount Type: None (OTA only)
• Aperture: 100 mm
• Focal Length: 900 mm
• Focal Ratio: f/5.0
• Star Magnitude Limit: 13.8
• Maximum Useful Magnification: 200×
• Rayleigh Resolution: 1.40"
• Light Gathering Power: 204×
• Tube Weight: 3.0 kg
• Tube Length: 920 mm
• Tube Diameter: 100 mm
• Focuser Type: Crayford
• Focuser Diameter: 2"
• Warranty Period: 60 months