ZWO FF90 APO Flat-Field Apochromatic Refractor
The ZWO FF90 APO Refractor is a lightweight, compact refractor telescope designed for visual observation and astrophotography.
*Focus is achieved within a 45–75 mm back focus range, measured from the M54–M48 interface shoulder.
Main Features
Flexible Connectivity for Multiple Configurations
Powerful Uniqueness
1. Lightweight & Compact
This unit features a 90 mm aperture and 609 mm focal length (f/6.8) for portability and performance.
The optical tube weighs 3.92 kg. Total system weight is 4.52 kg including the mounting rings and dovetail plate.
2. Four-Element Optical Design
The optics use a four-element, air-spaced apochromatic design. All elements work together to deliver a flat imaging field.
One ED glass element effectively reduces chromatic aberration. This results in superior color correction and image clarity.
3. 44 mm Image Circle — Full-Frame Support
With a 44 mm image circle, the unit supports full-frame sensors. It is ideal for use with an asiair pro for smart control.
It delivers sharp star fields with excellent edge-to-edge performance. This ensures consistent quality across the frame.
4. Native Flat-Field Design
The optical system features a native flat-field design. This eliminates the need for an additional field flattener.
Complex back focus calculations are not required. Simply attach your imaging setup and start capturing once focused.
Convenient Mechanical Design
5. Coarse & Fine Focus Adjustment
Equipped with a rigid 3-inch rack-and-pinion focuser, it offers precise 1:10 dual-speed coarse and fine adjustments.
A built-in 360° rotator at the rear allows for smooth, accurate camera angle adjustments during your session.
6. Retractable Dew Shield
This model features a retractable dew shield for portability. This helps protect your optical tube in the field.
Precision CNC machining and internal anti-reflection coatings help minimize stray light to enhance image contrast.
7. Quick-Release Mounting Rings
The mounting rings are detachable. This allows for quick and easy setup or teardown at any dark site.
8. Photography Extension Tube
The package includes a photography extension tube with a 2-inch filter thread and M48 and M54 adapters.
These components allow for easy integration with a wide range of modern imaging accessories and cameras.
Performance Charts
Optical Layout
Star Field Map
Product Diagram
Technical Specifications
In the Box
Warranty
ZWO 2-Year Warranty
