Schmidt Triplet for ZTF R. Dekany 16 April 2013

Add refigured Schmidt singlet to existing Grubb-Parsons doublet

Features of latest design April 15 Singlet remains plane parallel – Earlier quotes called for grinding a radius to one of the two existing plane surfaces New aspheric coefficient is about 70x smaller than the existing coefficient – … if original design is simply optimized Schmidt – Therefore, the ‘refiguring’ process for the singlet is fundamentally taking out much of the asphere Insensitive to axial location for installation – Could be either inside or outside existing doublet Relatively insensitive to axial location – 10 mm lateral misplacement barely affects image quality

Image quality (g’ shown) Evaluated assuming – g’ filter on inner 4 CCDs – R filter on outer 8 CCDs – … but it makes little difference after reopimizing Field curvature under control – Same design IQ out (beyond) corner of 16 CCD FPA