After doing our calibration of "best" mode, we measured Cinema (set up as Expert 1) at an awesome 898 lumens. That would be with the Iris set to Auto 1, for the best blacks the LG can achieve.
In the very "brightest" mode, (Vivid), we measured 1380 lumens. However, I played with several other "bright" combinations including Sports and Vivid, with color temp set, usually, to natural. The point is, you can have excellent color in a brightest mode, and still get 1100 to 1380 lumens depending on how good you want the color. For much of my sports viewing I used Expert 2
The Effect of zoom lens positioning on brightness: Our standard measurements reported for the LG CF181D are done with the zoom at its mid-point as with all reviews. Here are relative numbers based on Cinema mode (lamp on high, auto iris 1), for different lens positioning. From a percentage standpoint, the differences will be the same for any mode, as you change the lens angle. Basically wide angle is about 5% brighter than mid-point on the zoom, and telephoto would be about 13% dimmer than mid point.
Considering the zoom lens is a 1.8:1 zoom, that would indicate very good optics as the total drop is only about 18%! With many 2:1 zoom lenses (Panasonic, Epson...), the drop is about 40% from full wide, to full telephoto, and the LGs drop is less than half of that.
Note: Mike measured the effect of lens position, while the Cinema mode still had the iris at Manual 3 (about as dim as the LG is capable of), thus the low lumen numbers.
The 18% drop from wide angle to telephoto lens settings should be the same, regardles of what mode you choose.