Change the picture frequently. For variety, use some close-ups and some full body shots of the instructor. Zoom in on specific students as they ask questions. Move the camera around. Commercial television changes the picture every few seconds.
Commercial television is the comparison standard, emulate it.
Use ITV's capabilities. I played a 30 second clip of an episode of The Simpson's, when Lisa stole every Teacher's Edition book in her school, to illustrate how lost I would be without a specific MN State Department of Education manual that explained school finance. The students were pretty surprised to see the clip and it added to the emerging ITV-friendly culture in that class. ITV students have also seen other VCR tapes and a demonstration on ERIC data searches on a Macintosh. Using multiple sources of visual images makes educational ITV look more like quality television programming.