stereographic projection
立体照片投影，极射赤面投影

• dirt
• dirt optics
• dirt spot
• disability glare
• disalignment
• disappearing-filament optical pyrometer
• disc
• disc cam
• discerning method
• discernment
• discharge
• discharge chamber
• discharge current noise
• discharge excited
• discharger
• discharge tube
• disc laser
• disc of confusion
• discoloration
• disconnection
• discontinuity
• discontinuous wave
• discrete
• discrete-carrier hologram
• discrete channel