Diffraction-limited pixels versus number of lens elementsDavid ShaferDavid Shafer Optical DesignFairfield,CT 06824#203-259-1431shaferlens@sbcglobal.netNo nameUNITS:MMFOCAL LENGTH 100 NA 0.1111DES:Shafer33.9For any optical design with a givenfocal length there is some productof the pupil diameter D and thefull field angle A for which heUnanswered Questionsdesign can be made diffraction-limited over the whole field.1)For a 100 mm focal length design what is the maximum number of diffraction-limitedpixels possible with a one-element design,a two-element design,a three elementdesign,etc.D is the pupil diameter in mm and A is the full field angle in degrees2)What is the ratio of the maximum number of pixels divided by the number ofelements?And how does that change?Design Problem Groundrules100 mm focal lengthMonochromatic at .55uOnly BK7 glass lensesNo asphericsReal image on flat surfaceNO.07 waves r.m.s.or better over fieldBATHING,Distortion not relevantFISHING OR DOGSNon-zero center and edge thicknessALLOWED IN THIS LAKEand edge gaps to next lens.Real stop can be inside glassDO NOT ALLOW YOUR DOGS TO CHASE.WORRY OR INJURE THE WILDLIFENo vignetting