Optically tested on our in house test bench prior to dispatch at no extra cost to ensure you get a perfect telescope the first time around!
We are proud to introduce the new Sky-Watcher Professional ESPRIT 3-Element ED apochromatic refractors. These are instruments of the highest quality with optical performance rivalling or exceeding similar telescopes of even the most famous high-end telescope brands.
The ESPRIT Super Apo Triplets are designed for the most demanding astro-imagers but are also fine telescopes for visual observations. The premium, superbly-corrected optical systems deliver high-contrast images full of detail and zero detectable colour fringing, even on the brightest of objects.
An in house Zygo interferometer test & report is available with this telescope. Click here to read about the interferometer test in more detail. There are various packages available on this model. Please select from the packages above. The optical test and enhance includes a full inspection of the telescope, including optics, focuser, paintwork and other mechanical parts. A precise optical check is then performed then the scope is enhanced to ensure you get the best possible optical performance from your new instrument.

The interferometer is essentially a measuring instrument. Within the interferometer is a calibrated laser that is pointed through the optical test surface, then onto a high quality reference sphere, then back through the test subject then to an internal camera which gives us the measurement on the screen. From this, we can adjust the position of the test optic and the reference sphere to obtain a perfectly calibrated system. The more central the laser to the test optic and then on return, the better and more accurate reading and measurement we can take. This takes a lot of adjustment to get the best results from the optical surface. Once the measurement has been taken, we are provided with a series of results that show the optical quality of the surface plus other information. We will aim to provide 0.95 Strehl or higher. 
MAIN FEATURES:
3-Element Objective Lens, Focal Length 840mm (one Ohara FPL-53 and 2 x Schott lenses)
3” CNC Machined 11:1 Rotatable Dual-Speed Linear Power Focuser
Full-frame Corrected Focal Plane
Zero detectable Colour Fringing even on Bright Objects
Metallic High-Transmission Lens Coatings
Knife-edge Baffled Optical System
High-precision Mechanical Components
Aluminium OTA material (superior to plain carbon-fibre for this application)
Retractable Dew Shield
OTA Weight 9.61kg (without accessories), 12.13kg (with accessories)
3” DUAL-SPEED LINEAR POWER FOCUSER
3” LPF with 2” and 1.25” eyepiece adaptors and indexed scale
Zero focus-shift during focusing
High Load Capacity - holds up to 5kg of accessories whilst focusing and up to 10kg when locked.
New drawtube with steel sheet held by four large bearings makes focusing smoother than ever
The smooth focus motion and 11:1 fine focus wheel allows precision adjustment and critical focusing of eyepieces & cameras
Patent-pending design
ACCESSORIES SUPPLIED:
2” Dielectric Star Diagonal, 28mm 2” LET Eyepiece, 9x50 Right-Angled Erect Image Finderscope, Tube Rings and Dovetail Mounting Bar
Field Flattener Specifications:
An optically-matched M48-fitting doublet field flattener for Sky-Watcher's Esprit 120 ED PRO triplet refractor.
The M48 fitting provides a large clear aperture to reduce halation and a precision thread ensures the triplet and doublet lens groups are precisely aligned on the optical axis perpendicular to the image.
When used with the field flattener the Esprit-120 ED PRO's imaging circle is 44mm.
Notes
When fitting a DSLR camera you need only a M48 Ring to suit your Canon or Nikon camera. No additional spacers are required.
The spacing for dedicated CCD imaging cameras is 75mm from mating surface.
The rear thread is M48. When using T-threaded accessories you will need a M48-T adapter.