This drop-down menu allows you you to superimpose a grid on the false color image, for better locating the positions of features of interest. Possibilities are: No Grid (default); Q-Chi Grid (circles are in equal increments of momentum transfer, radial lines every ten degrees of azimuth), 2-Theta-Chi Grid (circles are in equal increments of scattering angle), or Qx-Qy Grid (square or rectangular grid). Notice that the grid is meaningless unless the calibration constants are set correctly (range, center, tilt, etc.).