aplanatic image formation
不晕成像，齐明成像

• false radiation
• false reflection
• family of curves
• family of ellipses
• family of half-curves
• fan
• fan antenna
• fan beam
• fan dial
• fan filter
• fan geometry mixing laser
• fan in
• fanning beam
• fanning strip
• fan out
• fan-shaped laser beam
• fantascope
• fan test object
• farad
• Faraday cage
• Faraday cell faraday configuration
• Faraday constant
• faraday dark space
• Faraday driver
• Faraday effect