ZWO FF80 APO Petzval Refractor – Full Frame Flatfield Astrograph

The ZWO FF80 is a premium apochromatic Petzval astrograph designed for full-frame astrophotography. With a focal ratio of f/7.5 and a 44mm image circle, this flatfield quadruplet delivers sharp, colour-accurate images across the entire frame. Two Extra-Low Dispersion (ED) glass elements minimise chromatic aberration, resulting in pinpoint stars and high contrast – even with large sensors like the ASI6200. Central RMS radius is an impressively tight 3 microns.

True Petzval Optics – No Backfocus Hassle

Unlike typical ED refractors that require precise backfocus spacing, the FF80’s fixed Petzval design removes the need to calculate sensor distance. You can connect filter wheels, off-axis guiders, and other imaging accessories without worrying about backfocus errors.

Built for Precision Imaging

With its fast f/7.5 focal ratio and generous image circle, the FF80 is ideal for advanced deep-sky imaging. The large 3″ rack-and-pinion focuser provides smooth and stable control with 10:1 microfocus for critical adjustments. It rotates 360°, letting you frame your target exactly how you want. The focuser also natively supports the ZWO EAF without requiring adapters.

All optics are fully multi-coated for maximum light transmission. Internally flocked baffles suppress reflections and stray light. The CNC-machined aluminium tube and brass focuser mechanism ensure long-lasting mechanical precision and rigidity.