Sky-Watcher Esprit 100EDX Apochromatic Telescope

The Sky-Watcher Esprit 100EDX is a premium apochromatic refractor built primarily for astrophotography, while also being well suited to demanding visual observation. Its three-element objective incorporates one Ohara FPL-53 ED glass element, while Sky-Watcher’s MHTC multi-coatings are applied to the optical surfaces. The optical design is intended to provide strong colour correction, high transmission and sharp, high-contrast images.

With a 100mm aperture, 550mm focal length and f/5.5 focal ratio, the Esprit 100EDX occupies a versatile position within the Esprit range. The 550mm focal length provides more image scale than the 70mm and 80mm models while retaining a relatively wide field, making it suitable for a broad selection of nebulae, open clusters and galaxies. The 100mm aperture also provides greater resolving power and light-gathering capacity for visual observation of the Moon, planets, double stars and deep-sky objects.

The telescope uses a CNC-machined 3-inch indexed drawtube with a dual-speed 11:1 hybrid rack-and-pinion focuser. The focuser is designed for high accessory load capacity and zero image shift. The focuser itself can be rotated independently, while a separate 360° rotatable adaptor on the drawtube provides additional control over camera orientation and image framing.

For astrophotography, an optically matched field flattener is available separately. OVL specifies an image height of 44mm when the optional field flattener is used. This should not be confused with an image circle: the manufacturer reports image height rather than a diameter measurement. No focal reduction factor is reported for the flattener, so it should not be described as a reducer.

The Esprit 100EDX has a non-retractable dew shield and an aluminium optical tube with internal baffling. The OTA is supplied with CNC-machined aluminium tube rings, a carrying handle, a 75mm Losmandy-style dovetail mounting bar and an aluminium carrying case. A 2-inch star diagonal can be fitted, but no diagonal, eyepiece or finderscope is included.