The first occasion when such filmed images were shown widely in public was during Dr Desmond Morris' BBC television series The Human Animal
(1994), in which a microscopic camera was present inside the vagina during ejaculation and orgasm, showing the ejaculation of semen, and a series of spasm-like movements during orgasm, which appeared to create a sucking effect that drew semen into the uterine cavity.
Since then, a more exploitative/pornographic approach has been taken in Dr Michael Perry's ostensible sex education video The Amazing G Spot & Female Ejaculation,
which finally hit DVD during August 2006, and is filled with images shot from within the vagina. This video may well be available at some torrent sites, although I haven't checked: click for a second link that has a couple of images