caa a22 4500 445371765 CHVBK 20180317142949.0 cr unu---uuuuu 170323e20110101xx s 000 0 eng 10.1007/s00340-010-4349-3 doi (NATIONALLICENCE)springer-10.1007/s00340-010-4349-3 Geometrical MTF computation method based on the irradiance model [Elektronische Daten] [P.-D. Lin, C.-S. Liu] The Modulation Transfer Function (MTF) is a measure of an optical system's ability to transfer contrast from the specimen to the image plane at a specific resolution. It can be computed either numerically by geometrical optics or measured experimentally by imaging a knife edge or a bar-target pattern of varying spatial frequency. Previously, MTF accuracy was generally affected by the size of the mesh on the image plane. This paper presents a new MTF computation method based on the irradiance model, without counting the number of rays hitting each grid. To verify the method, the MTF in the sagittal and meridional directions of an axis-symmetrical optical system is computed by both the ray-counting and the proposed methods. It is found that the grid size meshed on the image plane significantly affects the MTF of the ray-counting method, sometimes with significantly negative results. The proposed irradiance method is immune to issues of grid size. The CPU computation time for the two methods is approximately the same. Springer-Verlag, 2010 Lin P.-D Department of Mechanical Engineering, National Cheng Kung University, No. 1, University Road, 70101, Tainan, Taiwan aut Liu C.-S Department of Mechanical Engineering, National Cheng Kung University, No. 1, University Road, 70101, Tainan, Taiwan aut Applied Physics B Springer-Verlag 102/1(2011-01-01), 243-249 0946-2171 102:1<243 2011 102 340 https://doi.org/10.1007/s00340-010-4349-3 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00340-010-4349-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Lin P.-D Department of Mechanical Engineering, National Cheng Kung University, No. 1, University Road, 70101, Tainan, Taiwan aut NATIONALLICENCE 700 1- Liu C.-S Department of Mechanical Engineering, National Cheng Kung University, No. 1, University Road, 70101, Tainan, Taiwan aut NATIONALLICENCE 773 0- Applied Physics B Springer-Verlag 102/1(2011-01-01), 243-249 0946-2171 102:1<243 2011 102 340 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer