ɪn ˈɑːptɪks, tɹænsmˈɪʃən ɪz ðə pɹˈɑːpɚɾi əvə sˈʌbstəns tə pɚmˈɪt ðə pˈæsɪdʒ ʌv lˈaɪt, wɪð sˌʌm ɔːɹ nˈʌn ʌvðɪ ˈɪnsɪdənt lˈaɪt bˌiːɪŋ ɐbsˈoːɹbd ɪnðə pɹˈɑːsɛs.
In optics, transmission is the property of a substance to permit the passage of light, with some or none of the incident light being absorbed in the process.