>But what exactly is this "contrast" that is being measured? Can >anyone explain this? > > The ratio between the level of the representation of white and the level of the representation of black that make it through the system. Look at the contrast-sensitivity grating: http://tinyurl.com/avgda Maximum contrast is at the bottom; minimum is on top. A typical MTF curve is simply inverted. TTFN, Mark ---------------------------------------------------------------------- You can UNSUBSCRIBE from the OpenDTV list in two ways: - Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org - By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word unsubscribe in the subject line.