About this product
- Eliminate field curvature in short, optically fast refractor telescopes with this handy 38mm clear-aperture, fully multi-coated field flattener
- Designed for use with 400mm to 660mm focal length refractors with f/5 to f/7.5 focal ratios
- Optimizes your fast refractor telescope for astrophotography
- Preserves focal length attributes of the attached refractor telescope while flattening the field of view
- Compatible with 2" focusers and requires 55mm of backfocus, weighs 7.5 oz.