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Sky-Watcher Evostar EDX 100 APO f/7 Doublet Telescope
The Sky-Watcher Evostar EDX 100 represents a major architectural shift for the 100mm Evostar line. While the classic 100ED was renowned for its f/9 focal ratio, the new EDX 100 moves to a faster f/7 design, offering a wider field of view and significantly shorter exposure times for astrophotography. This transition to a "faster" system is supported by a complete mechanical overhaul designed to meet the rigors of modern imaging.
By utilizing an Ohara FPL-53 ED glass element, the EDX 100 maintains the color correction of its slower predecessor while offering a more compact and versatile form factor. It is a high-performance, diffraction-limited instrument that serves as a bridge between portable wide-field refractors and high-resolution planetary tools.
Apochromatic Performance at f/7
The move to f/7 increases the photographic speed of the telescope, but Sky-Watcher has ensured that optical integrity remains paramount. The ED doublet design features a positive crown element paired with a negative Ohara FPL-53 extra-low dispersion element. This combination virtually eliminates chromatic aberration, providing clean, high-contrast views of bright targets like the lunar limb or the rings of Saturn.
Each air-to-glass surface is treated with Metallic High-Transmission Coatings (MHTC), ensuring that 99.5% of light reaches your eyepiece or sensor. The result is an image free of ghosting and internal reflections, even when observing faint deep-sky objects near bright stars.
Redesigned Mechanical Suite
The EDX 100 is built for stability and precision. The most notable upgrade is the 2.8-inch indexed dual-speed 11:1 Crayford focuser. This larger drawtube is significantly more robust than the standard 2-inch versions, providing the stiffness required to hold heavy CMOS cameras and filter wheels without tilt or flexure.
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Integrated 360° Rotatable Adaptor: Framing your target is seamless thanks to the rotatable adaptor on the drawtube, allowing you to align your sensor without disturbing the focus.
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Retractable Dew Shield: The new sliding dew shield reduces the transport length to just 570mm, making the EDX 100 much more portable than the fixed-tube f/9 models of the past.
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Functional Carrying Handle: The CNC-machined tube rings are joined by a top rail that doubles as a carrying handle and an accessory mounting platform (Vixen-style).
The Perfect Mid-Sized Astrograph
With a native focal length of 700mm, the EDX 100 is perfectly sized for medium-to-large nebulae and galaxy clusters. For those seeking even more speed, an optically matched 0.92x Focal Reducer/Flattener is available, bringing the system down to f/6.44 for faster deep-sky acquisition. Whether you are a visual purist or a dedicated imager, the EDX 100 offers professional-grade features at a highly competitive price point.
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How does the EDX 100 compare to the older f/9 100ED?
The EDX 100 is significantly faster (f/7 vs f/9), which means it has a shorter focal length (700mm vs 900mm). This provides a wider field of view and requires shorter exposures for photography. Mechanically, the EDX is superior with a 2.8" focuser, a retractable dew shield, and an integrated rotator—features the older f/9 model lacked.
Does the faster f/7 ratio introduce more false color?
While faster doublets are generally harder to correct, the use of FPL-53 glass and modern lens figuring allows the EDX 100 to maintain excellent apochromatic performance. For visual use and most imaging scenarios, the chromatic aberration remains negligible.
Is a field flattener required for photography?
For small-sensor cameras (like 1/1.8" or 1" formats), you may not notice significant field curvature. However, for Micro Four Thirds, APS-C, or Full-Frame sensors, we highly recommend the dedicated 0.92x Reducer/Flattener to ensure sharp stars across the entire frame.
Can I use 2-inch accessories with this telescope?
Yes. The 2.8-inch focuser drawtube comes with an adaptor that accepts standard 2-inch star diagonals and accessories, as well as 1.25-inch eyepieces via a reduction adaptor.
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| Optical Design |
ED Doublet Apochromat |
| Aperture |
100 mm |
| Focal Length |
700 mm |
| Focal Ratio |
f/7 |
| ED Glass Type |
Ohara FPL-53 |
| Coatings |
Proprietary MHTC |
| Focuser |
2.8" Dual-Speed 11:1 Crayford |
| OTA Length (Retracted) |
570 mm |
| OTA Length (Extended) |
675 mm |
| OTA Weight |
5.5 kg (12.1 lbs) |
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Aluminum Carrying Case
× 1
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Tube Rings & Vixen-style Rail
× 1
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- Sky-Watcher 2-Year Limited Warranty
