Explore Scientific Field Flattener f/5 to f/7

The Explore Scientific Field Flattener corrects field curvature for sharp, round stars across your entire imaging sensor. Refractor telescopes produce a curved focal plane, but camera sensors are flat; without a field flattener, stars at the edges of your frame appear elongated or distorted. This fully multi-coated flattener with 38mm clear aperture corrects that curvature without changing your telescope's focal length or f/ratio.

The 2" barrel and M42x0.75 T-thread interface connect directly to your camera via a standard T-ring (sold separately). Back-focus distance is 55mm, matching the Explore Scientific corrector/reducer ecosystem for consistent spacing.

Note: This is an astrophotography accessory. It is not intended for visual use.

Key Features

• Fully multi-coated optics with 38mm clear aperture
• Corrects field curvature without changing focal length or f/ratio
• 2" barrel with M42x0.75 (T-thread) camera interface
• 55mm back-focus standard, consistent with the ES corrector/reducer ecosystem
• Premium high-gloss anodized aluminum construction

Ideal For

• Astrophotographers imaging with an f/5 to f/7 refractor who see stars smeared in the corners of the frame, the field curvature that grows with sensor size.
• Imagers who want to keep their telescope's focal length: the flattener corrects the field without reducing it, as a focal reducer would.
• DSLR and dedicated astronomy camera users, since a T-ring threads onto the flattener for either.

Accessories & Compatibility

• ES Essential Series: ED80, ED102
• ES FCD100 Series: 80mm, 102mm
• ES DAR Series: DAR102, DAR127, DAR152

Compatible with a broader range of Explore Scientific refractors than the 0.8x Focal Reducer, including the larger 127mm and 152mm DAR models.