About KAWAI SHIGERU
About オプト・イーカレッジ
About Optronics
About photographic lens
About lens(optics)
About diaphragm(optics)
About numerical aperture
About focal depth
About image formation(optics)
About optical system
About angle
About brightness
About focal length
About visual field
About F value
About fish-eye lens
About wide angle lens
About depth of field
About telephoto lens
About view angle
About Optical instrument elements and their materials
About Optical devices in general
About ひかり
About 結像
About 光学系