ZWO FF90 APO Flat Field Refractor with AM3N Mount Bundle - FREE TC40/PE160! - FF90+AM3N

This special bundle from ZWO includes the FF90-APO Refractor, the AM3N Harmonic Mount, and a FREE TC40 Tripod & PE160 Tripod Extension, for a savings worth over $500!  Offer good while supplies last!

About the ZWO FF90-APO Refractor....

Main Features

Flexible Connectivity for Multiple Configurations

Lightweight & Compact

The ZWO FF90 APO features a 90 mm aperture and 609 mm focal length (f/6.8), offering an excellent balance between portability and performance.

The optical tube weighs just 3.92 kg, with a total system weight of 4.52 kg including mounting rings and dovetail plate.

Four-Element Optical Design

The FF90 APO features a four-element, fully air-spaced apochromatic optical design. All four elements work together to deliver a flat imaging field without the need for an additional field flattener.

One ED (extra-low dispersion) glass element is incorporated to effectively reduce chromatic aberration, resulting in improved color correction and image clarity.

44 mm Image Circle — Full-Frame Support

With a 44 mm image circle, the FF90 APO fully supports full-frame sensors and a wide range of imaging setups.

It delivers sharp star fields with excellent edge-to-edge performance, ensuring consistent image quality across the entire frame.

Native Flat-Field Design

The FF90 APO features a native flat-field optical design, eliminating the need for an additional field flattener.

No complex back focus calculations or spacing adjustments are required—simply attach your imaging setup and start capturing once focus is achieved.

Convenient Design

Coarse & fine focus adjustment

Equipped with a rigid 3" rack-and-pinion focuser, the FF90 APO offers precise control with a 1:10 coarse & fine focus adjustment mechanism.

A built-in 360° rotator at the rear allows for smooth and accurate camera angle adjustments.

Retractable Dew Shield & Quick Release Mounting Rings

The FF90 APO features a retractable dew shield, reducing overall length for improved portability.

Precision CNC machining and a high-quality painted finish, combined with an internal anti-reflection coating, help minimize stray light and enhance image contrast.

The mounting rings are detachable, allowing for quick and easy setup or teardown of the telescope.

Photography Extension Tube 

The FF90 APO includes a photography extension tube with a 2-inch filter thread, along with rear adapters in M48×0.75 and M54×0.75 standards.

This allows for easy integration with a wide range of imaging accessories.

Performance

Ray Tracing

Spot Diagram

Mechanical Drawing

Specifications

What's in the box?

FF Series Telescope Comparison

About the ZWO AM3N Mount...

ZWO developed the special strain wave gear used in the AM5N based on the actual needs for astrophotography. The strain wave gear system comes with very low periodic errors, smooth gearing, and high torque.

The AM5N mount’s internal structure is optimized with a strain wave gear reducer and synchronous belt, delivering precise control and an impressive 300:1 reduction ratio.

Each mount is tested and shipped with an individual periodic error (PE) curve report.

ZWO measures each mount and equips it with an exclusive PE curve before it leaves the factory. The X-axis represents the drive angle, and the Y-axis represents the periodic error. The periodic error is consistently controlled within ±15 arcseconds.

Integrated Type-C and DC Power Ports

The upgraded AM3N weighs just 4.1 kg (9.04 lbs), with a newly optimized body design for better portability and cable management.

The dovetail saddle now includes both a Type-C and 12V DC output port, helping eliminate cable clutter and reducing the risk of tangling — no more cable mess.

Additionally, it includes a magnetic hex wrench that attaches securely to the mount body, ensuring convenient access and storage.

Powerful Payload Capacity: 8 –13 kg

It can support up to double its own weight 8 kg (17.64 lbs) without counterweights,and over triple its weight 13 kg (28.66 lbs) when used with counterweights.

This payload capacity easily accommodates a wide range of telescopes, providing a solid and reliable foundation for your observing and imaging needs.

Based on internal testing:

1. Maximum load without the counterweight: 8 kg (17.64 lbs) (maximum output torque: 16N · m);

2. Supported counterweight: ≤ 5 kg (11.02 lbs). Maximum load capacity with the counterweight: 13 kg (28.66 lbs).

The counterweight should be secured on a counterweight bar of no more than 25 cm (9.84 in) in length.

Equatorial Mode / Altazimuth Mode

Can be switched via SkyAtlas App or Hand Controller.

All-round 0°-90° Altitude Scale

The AM3N features a versatile altitude adjustment design ranging from 0° to 90°, allowing for unrestricted use across both low and high latitude regions.

Gear 1: Rotate the altitude gear tension knob to achieve a scale between 0 and 60.

Gear 2: Loosen M6 hex wrench and then adjust the altitude gear fine adjustment knob to achieve a scale between 30 and 90.

Evolved Portable Control - Wi-Fi & Bluetooth Connectivity

Easily Controlled with Mobile Apps

The app offers an onscreen joystick, including Tonight’s Target, GOTO, Live Preview and so many great functions can all be achieved with your phones.

There is no need to connect to a computer—the mount and Hand Controller connect via Wi-Fi.

The mount is compatible with ASCOM, INDI, ASIAIR, and other platforms.

Seamless ASIAIR Integration

ASIAIR can connect to the AM3N wirelessly or via cable, offering full control at your fingertips.  Enjoy the ultimate astrophotography experience with the ZWO Ecosystem, where all your gear works together—flawlessly.

About the ZWO FREE TC40 Tripod...

The ZWO TC40 Tripod, made from carbon fiber, has an amazing 110 pound (50kg) weight capacity.  It works great with the ZWO AM5 or AM3, but is also compatible with other mounts, such as the iOptron GEM45 & CEM40, the Sky-Watcher AZ-GTi, or the Rainbow Astro 135E.

The adjustable height of the TC40 Tripod is 470 mm to 800 mm.  The legs are in two sections, with the upper section having a leg diameter of 40 mm.  The lower section is just a tad smaller at 36 mm diameter.  A spreader plate pushes up agains the legs as you turn the knob, increasing the stability of the legs and locking them in place.

The TC40 can be folded for transport and storage to just 500 mm long.  The tripod head plate and weight bag can be removed to make the load a little lighter, but the TC40 weighs in at just over 5 pounds, or 2.3 kg.

The weight bag mentioned above attaches to the legs near the bottom of the tripod.  By filling it with something heavy, you can further stabilize the tripod.  A good choice would be your telescope's battery pack, but you can always add stones!

The TC40 tripod head plate offers three mounting points for a sturdy and secure connection. In its standard configuration, the tripod head plate will attach to the AM5 mount base.  Turn it upside down to present a 3/8" tapped hole for mounting compatible mounts to the tripod.  A lock knob is on the side of the tripod head that will reinforce the connection between the mount and the tripod.

About the ZWO FREE PE160 Pier Extension...

The ZWO 160 mm Pier Extension for the AM3 or AM5 mount has a diameter of 124 mm and can handle a load capacity of more than +/- 10 kg!  The pier extension has a hallow-carved design to decrease weight (just 1.0kg!) and is CNC machined of aircraft grade aluminum, making it resistance to high temperatures, deformity and wear.