Thanks, PE. I thought it might. MTF was a term that was thrown around a lot by the people from the research labs when I was at EK. Unfortunately, due to very active patent wrangling with another photographic company, all of that stuff was kept on a strictly need to know basis - (I didn't do any work directly with imaging so I didn't need to know) - and there wasn't any wikipedia or Internet back then. I will check out those references and find a better forum if I have more questions.