The Epsilon-180ED Newton F/2.8 hyperbolical design
The Epsilon-180ED is a catadoptric reflector, including an hyperbolical primary mirror, an elliptical secondary mirror and a 2-lenses field corrector in the rack-and-pinion focuser. It results a perfectly flat field, ideal for wide field imaging.
Spot-diagrams
The perfect correction of field, covering the entire image circle, is attested by the spot-diagram. The diffraction pattern almost does not present a residue of coma in periphery. In the same way, the 2-lenses corrector practically does not generate any chromatism.
