астр.; техн.; физ. светосила
светосила прибора
фіз. light power;фот. aperture ratio, speed, candle power.
"Honor is not the exclusive property of any political party." Herbert Hoover
"Hitch your wagon to a star." Ralph Waldo Emerson
"If fear is cultivated it will become stronger, if faith is cultivated it will achieve mastery." John Paul Jones
"Ambition is but avarice on stilts, and masked." Walter Savage Landor