In my working with LCDs....there is no Intensity. Just Contrast. LCDs work by crystals that would normally set in one of two orientations. In one direction they let light pass through and in the other they do not let light go through. The crystals are said to be twisted from one positon to the other by applying a DC bias across them. The amount of bias controls how far they twist. However the amount of twist and how fast they can change from one state to the other is also dependent upon other factors one of which is temperature.

If you take an LCD in hand that has a variable bias supply hooked up it is possible to watch the effect of changing the bias level. At a given viewing angle the bias adjustment range can take the display from a state where ON pixels (segments) are barely visible and of similar appearance to OFF pixels (segments). At the other extreme of the bias level the OFF pixels will become quite dark and become almost indistinguishable from the ON pixels or segments.

You can also observe, particularly at the intermediate levels of bias voltage, that if you tip the display to a different viewing angle the appearance of the display will change similar to the way the bias voltage changes the pixel look for a fixed viewing angle.

Hope this helps
Mike Karas