ZWO 90mm Quad APO Refractor Total eclipse The Explore Scientific field flattener

The Explore Scientific field flattener is designed to work with telescopes with focal ratios between f/5 and f/7

Take Your Astroimaging Studio Anywhere

when the planet is near the horizon

These models stand less than 3" out of your focuser and the 5x takes 1¼" threaded filters

ZWO 90mm Quad APO Refractor Total eclipse The Explore Scientific field flattenerIf this scope looks familiar, that's because it is the ZWO rebrand of the Askar 91 F Series. The FF90 APO's 609mm f 6. 8 optics cover a full frame, 44mm imaging circle, and can be used for both visual observation and astrophotography. The telescope's four element designincluding an ED elementmeans no more precisely calculating your backfocusif you've got accurate focus, you'll get sharp stars out to the edges of your image. This also means there's no