The paper describes an achromatic Steinhal type doublet that employs an aspherical surface to allow wide angle imaging. A design criteria, optimization techniques and tolerancing of the doublet are described. Further a manufacturing process of the system and achieved optical performance measurement is discussed. Benefits of the wide angle imaging doublet are recently planned to be used in automotive industry application, namely for optimizing of head-light performance and their final evaluation. The final device is planned to be part of the production line.
The 8-inch Clark objective lens of the Astronomical Institute of the Czech Academy of Sciences is probably the oldest doublet used for professional astronomical observation in the Czech Republic. Its optical imaging performance has become legendary among several generations of professional astronomers. The lens was manufactured by Alvan Clark in Cambridge, Massachusetts at the end of the 1850s. The 8-inch refractor functioned as the main telescope of the astronomical observatory in Ondřejov in the first half of the twentieth century. The objective has been cleaned and restored twice in the TOPTEC Centre in Turnov. We had the opportunity to measure the optical parameters of the doublet during its time in Turnov and we subsequently evaluated its residual aberrations. This paper is a record of the results of the optical simulations.
The Auxiliary Full-Disc Telescope (AFDT) will be used for the orientation of the observer on the solar disc
and in its surroundings, for an easy guidance of the European Solar Telescope (EST) to a selected target,
and for precise coordinate measurements. AFDT can be used as an autonomous robotic telescope for synoptic
observations and records of solar activity also when no observations are carried out at the EST main telescope.
The principal functions of AFDT and the related requirements are summarised. The specific axial mechanical
structure accommodating the refractor optical system is outlined. The optical system and its components are
described. Two alternatives of the positional control system - the active guiding system and the passive guiding
system - are described and their functionality is analysed.