Sky-Watcher 0.9x Reducer / Flattener for Evostar 62ED

The Sky-Watcher 0.9x Reducer / Flattener for Evolux 62ED is a high-performance optical accessory that transforms your telescope into a faster, wider imaging system. By reducing the focal length by a factor of 0.9x, it effectively shifts the focal ratio from ƒ/6.45 to a swifter ƒ/5.8, which results in a significant 24% reduction in required exposure times. Beyond just increasing speed, this two-element design—which incorporates an ED glass element—serves as a dedicated field flattener. This is essential for astrophotographers as it corrects field curvature, ensuring that stars remain sharp, pinpoint, and free from elongation right to the very edges of your image sensor.

For seamless integration into your imaging train, the unit is designed with a standard 55mm backfocus distance, making it compatible with a wide range of DSLR and dedicated astronomy cameras. It attaches securely to the Evolux 62ED focuser via an M56x1 female thread and provides an M48x0.75 male thread on the camera side to minimize vignetting on larger sensors. Additionally, the included adapter/field rotator features a built-in cavity that accepts standard 2-inch filters, allowing you to easily use light-pollution or narrowband filters without the need for extra spacers.

Product Features in Detail

Optimized for Fast Imaging

By dropping the focal ratio to ƒ/5.8, this reducer allows you to capture the same amount of light in roughly three-quarters of the time compared to the native scope. This is a massive advantage during short nights or when trying to maximize data collection on faint nebulae.

Professional Edge Correction

Refractors naturally suffer from a curved focal plane. This flattener "levels" that field, ensuring that the stars in the corners of your APS-C sensor are just as sharp and round as those in the center, removing the need for aggressive cropping.

High-Performance ED Glass

Unlike generic reducers, this unit utilizes an ED (Extra-low Dispersion) element. This ensures that the reducer doesn't introduce chromatic aberration (color fringing), preserving the high-end apochromatic performance of the Evolux 62ED objective lens.

Built-In Field Rotator

The included adapter functions as a field rotator, allowing you to turn the camera to perfectly frame your target without having to loosen the focuser or lose your focus position. This is essential for precisely composing large targets like the North America Nebula.

Clean Filter Integration

Because the reducer accepts 2-inch filters internally, you don't need a separate filter drawer or wheel for basic imaging. This keeps the weight of your imaging train closer to the mount, improving balance and reducing mechanical strain.

Wide-Field Perspective

With an increased field of view of approximately 5.09°, this reducer turns the 62ED into a "wide-field monster," capable of capturing entire constellations or sprawling deep-sky complexes in a single frame.