Equally suited to observation and astrophotography, the FF90 APO Refractor Telescope from ZWO features a quadruplet air-spaced apochromatic lens system that eliminates the need for a separate field flattener. The quad APO includes one extra-low dispersion element and dramatically reduces chromatic aberration. It also eliminates the need to calculate back focus distance—just attach your camera with one of the four included adapters and you're ready for imaging. The f/6.8 focal ratio and 609mm focal length collect the light needed for long-exposure, deep-sky photography, but add a diagonal with a high-magnification eyepiece and the scope is ideal for planetary observation.
Optical Tube Assembly
- f/6.8 focal ratio and 609mm focal length allow for both deep-sky and planetary imaging
- Quadruplet air-spaced apochromatic refractor design with one ED element produces rich views with minimal chromatic aberration
- APO is self-flattening, eliminating the need for a separate field flattener
- Supports 44mm image circle for full-frame cameras
Focuser
- Sturdy 3" rack-and-pinion focuser easily carries large and heavy eyepieces, accessories like Barlows and focal reducers, and imaging systems
- 2" and 1.25" adapters
- 360° rotator with scales and finder base
- 10:1 fine adjustment ratio
Use and Handling
- Anodized red handle and tube ring assembly can be detached and reinstalled in seconds
- Photography extension tube with M54 and M48 adapters
- Retractable dew shield's interior is matte painted to reduce reflections
- CNC-machined aluminum optical tube
- Finderscope bases on both sides of focuser and base slot on handle
- 230mm Vixen-style dovetail plate