Imaging system for spectrograph with multichanell Šolc filter

Solving the problem of solar spectrograph telescope,we have made research of possible imaging systems for spectrograph with multichanell Šolc filter.We have decided to use off-axis unobstructed Maksutov telescope,which is able to meet our demands for constant solar image scale in wavelenght within 380 to 760 nm.This telescope provides good image contrast similar to apochromatic objective lens uses only classical materials. Diameter of the telescope is 140 mm,focal length is 2000 mm