The FRA400 quintuplet astrograph has adopted modern optical design with a retractable dew shield, a 3" rack-and-gear-based high-precision reducer containing a 360-degree rotator, M68×1 thread, a 2" adapter ring and a 1.25" visual adapter. The reducer is equipped with fine focal adjustment function for more precise calibration in practical observation or sky imaging.
It’s excellent in controlling and possibly avoiding chromatic aberrations. The image quality is also optimized to satisfy various observing or imaging purposes.
It’s worth mentioning that FRA 400/5.6 has a pair of fashionable-looking and multifunctional patented tube rings. Various practical attachments are available on three sides of the tube rings which is really a convenience for practical observation or imaging activities.
Focal length: 400mm
Focal ratio: F5.6
Objective type: Quintuplet dual ED air-spaced APO
Image circle: 44mm
Back focus: 140mm (from the end of rotator M68x1 thread)
Overall length: 317mm
Options weight: 2.88kg
Back-end adapter: M68×1 male thread, 2" adapter/1.25" adapter
Accessories: a pair of tube rings, a handle, a dovetail plate, an
inspection list, a manual