ZWO FF110-APO 110mm Quadruplet Refractor F/7.0

Flat-Field 4-Element Optics at f/7

This refractor's quadruplet optical design provides apochromatic color correction and a natively flat field, eliminating the need for a separate flattener. This simplifies your imaging train and removes the complexity of calculating back focus; as long as you can achieve focus, the starfield is sharp edge-to-edge. The 766mm focal length frames many popular deep-sky targets like the Horsehead Nebula (Barnard 33) and the core of the Andromeda Galaxy (M31) with room to spare on full-frame sensors.

Rigid 3-inch Dual-Speed Focuser

To prevent image shift and flexure with heavy cameras and filter wheels, the FF110-APO is built with a robust 3-inch rack-and-pinion focuser. The dual-speed 1:10 fine adjustment knob allows you to achieve critical focus with precision, which is essential for resolving fine detail. This large-format focuser ensures the optical path is never vignetted, even with large full-frame camera sensors.

ZWO FF110-APO vs. ZWO FF90-APO

The primary distinction between the ZWO FF110-APO and its smaller sibling is between image scale and portability.

• ZWO FF90-APO Advantage: At 9.97 lb, the FF90 is substantially lighter than the 14.9 lb FF110-APO, allowing it to be used on smaller, more portable equatorial mounts.
• ZWO FF110-APO Advantage: The FF110-APO's 766mm focal length produces a larger image scale than the FF90's 609mm. This allows you to resolve more detail on smaller galaxies and planetary nebulae with the same camera sensor.

Imaging-Ready at 14.9 lb

The FF110-APO includes essential hardware to get you mounted and imaging quickly, including a set of mounting rings and a standard Vixen-style dovetail plate. A key trade-off for its optical power is the 14.9 lb weight with handle, rings and dovetail. This requires an equatorial mount in the EQ6/CEM40 class or greater to ensure stable, unguided exposures and reliable tracking for long-exposure astrophotography.