Roo, my first thought when I read this was that you are thinking of the difference between shows shot on film versus shows shot on tape. Usually 1-hour drama style shows are shot on film, while some sitcoms and nearly all variety-style shows (with a live audience) are shot on tape. The difference in appearance is very obvious.
However, I know for a fact that LnC was always shot on film, never on tape. So I'm not really sure about the difference you are speaking about. I personally never noticed any kind of change in the appearance of the show. I did see how the actors' appearances changed over time.
Sorry - I know that doesn't answer your question.
Lynn