The SharpStar 2.5" field flattener is one of the best and most universal correctors for apochromatic refractors. It delivers a fully illuminated circle for the full frame (24mm x 36mm) and a corrected image circle up to 55mm. Differently from many other flatteners, it does not reduce the native focal length of your telescope. In other words, its magnification is x1.0. This allows the full use of the power of the telescope.
The flattener is suitable for several apochromatic refractors with a focal ratio between f/5 and f/9, a focal length between 500mm - 1000mm and a backfocus of 145mm. This distance is quite common in refractors. Considering the large 61.5mm aperture of the flattener, it is suggested to use it on focusers with a diameter of at least 2.5".
$250
Dimitri 0429356751
Last edited by UKR1; 19-02-2025 at 08:41 PM.
Reason: sale pending
