Strictly speaking, the slow transition from line-of-sight to scattered deposition is determined not only by pressure (or mean free path) but also by source-to-substrate distance.
stɹˈɪktli spˈiːkɪŋ, ðə slˈoʊ tɹænsˈɪʃən fɹʌm lˈaɪnʌvsˈaɪt tə skˈæɾɚd dˌɛpəzˈɪʃən ɪz dɪtˈɜːmɪnd nˌɑːt ˈoʊnli baɪ pɹˈɛʃɚ ɔːɹ mˈiːn fɹˈiː pˈæθ bˌʌt ˈɔːlsoʊ baɪ sˈoːɹstəsˈʌbstɹeɪt dˈɪstəns.