FF90 APO Flat-Field Apochromatic Refractor/FF90 APO Bundle M54 adapter For curved focusers like the

For curved focusers like the one in the image above

Ensure that the bracket is flush with the EAF mounting surface without any gaps

Please watch the picture below carefully

the FF131 APO offers precise control with a 1:10 coarse & fine focus adjustment mechanism

Quantum efficiency(QE) -Main sensor

FF90 APO Flat-Field Apochromatic Refractor/FF90 APO Bundle M54 adapter For curved focusers like theLightweight & Compact Designed for Both Visual Observation and Astrophotography *Focus can be achieved within a back focus range of 4575 mm, measured from the M54M48 interface shoulder. Main Features Flexible Connectivity for Multiple Configurations Uniqueness 1. 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