System for analysing a collimated light beam guided by a beam guiding optical unit, comprising • a first Fourier optical unit (110, 510) which is formed by a first focusing lens element having a first focal length (f 1); • a graduated neutral density filter arrangement (120, 520) which in relation to the beam path is arranged downstream of the first focusing lens element at the distance of the first focal length (f 1); • a second Fourier optical unit (130, 531, 532, 533) which is formed by a second focusing lens element having a second focal length (f 2) and which in relation to the beam path is arranged downstream of the graduated neutral density filter arrangement (120, 520) at the distance of the second focal length (f 2); and • a light intensity sensor arrangement (140, 540) which in relation to the beam path is arranged downstream of the second focusing lens element at the distance of the second focal length (f 2), the light intensity sensor arrangement (140, 540) having at least one light intensity sensor (141, 541, 542, 543); • wherein the light intensity sensor arrangement (140, 540) is designed such that it measures, for each graduated neutral density filter (121, 521, 522, 523) of the graduated neutral density filter arrangement (120, 520), in each case the light intensity transmitted by said graduated neutral density filter; and • wherein the graduated neutral density filter arrangement has a first graduated neutral density filter with a linear transmission profile in a first spatial direction and a second graduated neutral density filter with a linear transmission profile in a second spatial direction, which differs from the first spatial direction, and/or wherein the graduated neutral density filter arrangement has at least one graduated neutral density filter with a transmission profile that is parabolic at least in a predetermined spatial direction. • a first Fourier optical unit (110, 510) which is formed by a first focusing lens element having a first focal length (f 1); • a graduated neutral density filter arrangement (120, 520) which in relation to the beam path is arranged downstream of the first focusing lens element at the distance of the first focal length (f 1); • a second Fourier optical unit (130, 531, 532, 533) which is formed by a second focusing lens element having a second focal length (f 2) and which in relation to the beam path is arranged downstream of the graduated neutral density filter arrangement (120, 520) at the distance of the second focal length (f 2); and • a light intensity sensor arrangement (140, 540) which in relation to the beam path is arranged downstream of the second focusing lens element at the distance of the second focal length (f 2), the light intensity sensor arrangement (140, 540) having at least one light intensity sensor (141, 541, 542, 543); • wherein the light intensity sensor arrangement (140, 540) is designed such that it measures, for each graduated neutral density filter (121, 521, 522, 523) of the graduated neutral density filter arrangement (120, 520), in each case the light intensity transmitted by said graduated neutral density filter; and • wherein the graduated neutral density filter arrangement has a first graduated neutral density filter with a linear transmission profile in a first spatial direction and a second graduated neutral density filter with a linear transmission profile in a second spatial direction, which differs from the first spatial direction, and/or wherein the graduated neutral density filter arrangement has at least one graduated neutral density filter with a transmission profile that is parabolic at least in a predetermined spatial direction.