ZWO FF70 APO Refractor OTA

Description

ZWO 70 mm Flat-Field Apochromatic Refractor OTA

A compact astrograph designed for serious astrophotography

The ZWO FF70 APO is a 70 mm apochromatic refractor specifically designed for astrophotography. Its 70 mm aperture, 490 mm focal length, and f/7 focal ratio provide an excellent balance between field of view, image brightness, and portability. Unlike conventional refractors, this telescope is engineered from the ground up to deliver a naturally flat image field, allowing users to attach a camera and begin imaging without additional optical correctors. At only 3 kg including its mounting hardware, the FF70 APO is particularly well suited for portable imaging setups and travel astrophotography, where minimizing weight without sacrificing optical performance is essential.

Native flat-field optics for simpler imaging setups

One of the FF70 APO's biggest advantages is its four-element apochromatic optical design. Three elements form the main objective, including an ED (extra-low dispersion) glass element that effectively suppresses chromatic aberration, while a fourth integrated element flattens the image field. This design eliminates the need for an external field flattener and removes much of the complexity associated with spacing calculations. Once focus is achieved, the imaging train is automatically positioned at the correct optical distance, allowing astrophotographers to spend less time adjusting equipment and more time capturing data.

Full-frame support with sharp stars from edge to edge

The FF70 APO provides a generous 44 mm image circle, making it fully compatible with modern full-frame astronomical cameras. Many compact refractors exhibit star distortion near the edges of large sensors, but the FF70 APO is designed to maintain image quality across the entire field. This is particularly important for wide-field astrophotography, where large nebulae, star clouds, and extended deep-sky objects benefit from uniform sharpness throughout the frame.

Precision focusing built for astrophotography

The telescope is equipped with a robust 2.4-inch rack-and-pinion focuser featuring a 1:10 dual-speed reduction mechanism. Fine focus adjustments are critical in astrophotography because even tiny focus errors can noticeably reduce image sharpness. A built-in 360° camera rotator allows precise framing without disturbing the rest of the imaging setup. This enables users to easily align galaxies, nebulae, and star fields exactly as desired before beginning an imaging session.

Portable design with practical details

The FF70 APO incorporates several design features aimed at field use. A retractable dew shield shortens the telescope for transportation while helping to reduce dew formation during observations. Internal anti-reflection treatment minimizes stray light and improves image contrast. The included quick-release mounting rings, Vixen-style dovetail plate, and photography extension tube simplify installation and accessory integration. Standard M48×0.75 and M54×0.75 adapters ensure compatibility with a wide range of astronomical cameras, filter drawers, and imaging accessories.

Suitable for visual observation too

Although primarily designed as an astrograph, the FF70 APO can also be used for visual astronomy. By removing the supplied photography extension tube, users can attach an optional diagonal and eyepiece through the standard 2-inch connection. Its 70 mm aperture and 140× maximum useful magnification make it suitable for observing the Moon, planets, and brighter deep-sky objects. However, its optical design clearly prioritizes astrophotography performance over general-purpose visual use.

Who is this product for?

• Intermediate and advanced astrophotographers
• Users building portable imaging setups
• Full-frame camera owners
• Deep-sky imaging enthusiasts
• Travelers looking for a lightweight astrograph

This telescope is not intended as a beginner's first visual telescope. Its strengths are fully realized when paired with dedicated astrophotography equipment.

What's in the box

• ZWO FF70 APO optical tube
• Quick-release mounting rings
• Vixen-style dovetail plate
• Photography extension tube with integrated 2-inch filter thread
• M48×0.75 adapter
• M54×0.75 adapter
• Retractable dew shield