Native Contrast refers to the maximum difference possible if the most light and most dark image were on the same frame. Dynamic is the theoretical difference of the most light and most dark, by means of backlighting tricks and the like that the panel is able to do.
Dynamic contrast (in a very basic sense) turns the backlight all the way up and measures the white there, and then turns the backlight all the way down, and measures the black there. This is fine for your blacks in a dark scene or whites for a white scene, the backlight is on full or 0.
Static contrast is measured in one screen, and is the 'real world' figure (if any contrast ratio could be called that). What that means is a measurement of the white and black on the screen at once. Why its significantly less is because any backlight moving up / down will of course hurt the opposite colour. (I.e. turning the backlight down will decrease the whites, turning the backlight up will decrease your black). This is what a TV has to deal with all the time however with a normal day (white clouds) with shadows on the screen for example.
dont compare with the dynamic contrast ratios wen comparing lcd
LG uses some diff sort of calculation to mention dynamic contrast...n get high no's....
700:1 std contrast ratio is a
very good no. TN...the dell ultrasharp has 1000:1.