Sky-Watcher f/4 Aplanatic Coma Corrector – Quattro Newtonians

Sky-Watcher f/4 Aplanatic Coma Corrector – Quattro Newtonians

Description:
The Sky-Watcher f/4 Aplanatic Coma Corrector is specifically engineered for fast f/4 Newtonian telescopes of the Quattro series. Its four-element optical design, including FPL51 ED glass, delivers outstanding coma correction across a flat imaging field, ensuring pinpoint stars from center to edge.

Unlike generic correctors, this model is optimized for f/4 systems and preserves the native focal ratio without magnification change. It produces a fully corrected image circle with sharpness maintained even at the corners—ideal for wide-field astrophotography using APS-C and full-frame sensors.

It requires a standard 55 mm backfocus and connects via an M48x0.75 camera thread. A separate DSLR-M48 adapter is needed for DSLR use. The corrector supports standard 2" filters and inserts directly into 2" focusers without mechanical obstruction inside the tube.

Astrophotographers have reported significantly better performance compared to standard coma correctors like the Sky-Watcher 0.9x or Baader MPCC III, especially with Quattro reflectors. The result: clean, undistorted star shapes and excellent edge sharpness.

Technical specifications:

• Optical design: 4 elements, including FPL51 ED glass

• Required backfocus: 55 mm

• Image circle: 28 mm

• Outer diameter: 50.8 mm (2")

• Camera thread: M48x0.75

• Filter thread: accepts 2" filters

• Compatibility: Sky-Watcher Quattro f/4 Newtonians (200/800, 250/1000, 300/1200)

• DSLR adapter: required (M48 ring, not included)

• Weight: approx. 310 g

Additional information:

• No focal length change (1.0x native)

• True aplanatic correction for wide-field imaging

• Compatible with APS-C and full-frame sensors

• Delivers pinpoint stars across the entire field

• Designed specifically for f/4 Newtonians

• Not suitable for slower Newtonians (f/5 or f/6)