zero-power air-spaced doublet
零屈光度空气隙双[分]透镜

• oven
• overactive
• overal frequgncy response
• overall accuracy
• overall attenuation
• overall cavity gain
• overall dimensions
• overall efficeincy
• overall f-number
• overall focal length
• overall integral metering
• overall length
• overall magnification
• overall size
• overall system gain
• overannnealing
• overarm
• overarm support
• overbalance
• overbunching
• overburden
• overcast
• overcharge
• overcoat
• overcoating