Projected 2D power spectrum (in arbitrary units) for a conical 3D geometry and a perturbation field with a power spectrum P(k) ~ k^{− 8 / 3} (dashed line). The solid curves show the recovered shape of the power spectrum for different inclination angles of the axis of the cone with respect to the plane of the sky. Here θ = 0 means that the cone is placed exactly in the plane of the sky, while for θ = π/ 2 is projected along the line of sight.