Theoretical visibility distributions (right panels from (d) to (f)) corresponding to intensity distributions (left penels from (a) to (c)). Red dashed lines denote FWHM and black dashed lines denote radius. Blue (panels (a) and (d)), orange (panels (b) and (e)), and green (panels (c) and (f)) solid lines mean Gaussian, uniform disk, and sphere intensity distributions, respectively. All visibility distributions show the same FWHMs.