单词	f-number
释义	f-number noun f-num·​ber ˈef-ˌnəm-bər  1 : the ratio of the focal length to the aperture in an optical system 2 : a number following the symbol f/ that expresses the effectiveness of the aperture of a camera lens in relation to brightness of image so that the smaller the number the brighter the image and therefore the shorter the exposure required Word History Etymology focal length First Known Use 1898, in the meaning defined at sense 1
随便看	athínai Ati Atikokania atilt atilter atiltest atingle ation atiptoe atis atishoo Atitlán Atiuan ative Atjehnese Atka Atka mackerel Atl atlant- Atlanta atlantae atlantan atlantans atlantas Atlantean

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