You can't tell that way... Strap it down to a stool, spool it up slowly and see which blade tracks where. (at 3/4 throttle roughly) If one is higher than the other, you'll have to either bring the low one up by adding pitch to that one, or bring the high one down by reducing pitch on that one. Look at them straight on from the side, and the different colored stripes should make it easy to see if there tracking in the same plane.