William Optics FLT91 Flat6A III Special Edition

William Optics FLT91 Flat6A III Special Edition: custom-calculated for the FluoroStar 91

This Special Edition of the Flat6AIII is specifically calculated for the William Optics FluoroStar FLT91. Every refractor naturally produces a slightly curved image field; a flat camera sensor cuts through this, causing stars in the corners to stretch into streaks. A flattener corrects for this curvature so that stars remain small and round all the way to the corners. Especially with a fast triplet like the FLT91 (around f/5 to f/7) and large sensors, a custom-calculated flattener is the difference between good and tight corners.

The flattener mounts via the 2-inch connection of the FLT91 and comes with a camera adapter featuring a fixed, pre-calculated back focus distance: the sensor is thus positioned directly at the correct spot, without measuring or spacer rings.

Why a dedicated flattener per telescope

Field curvature varies per optical design. A universal flattener provides average correction; this edition corrects the curvature of the FLT91 precisely.

Featured accessories

Connect your camera using the included adapter and your camera's T2 ring or M48 adaptermerk.

For whom yes and for whom no

• ✓ Owners of a FluoroStar FLT91 who do astrophotography
• ✗ Owners of other WO apos: choose the flattener calculated for your model

Specifications

You can find more accessories for this brand at the William Optics brand page.