A security element comprising: an array of focussing elements defining a focussing element plane, each focussing element being adapted to focus light only in a first direction, the focussing elements being arranged in a regular array along the first direction (Lv); an array of image strips (100, 200, 300) overlapping the array of focussing elements, the array of image strips (100, 200, 300) comprising at least a first set of image strips and a second set of image strips, wherein the first and second sets of image strips (100, 200) are interlaced along the first direction (Lv), and wherein the first and second sets of image strips each have a periodicity along the first direction that is substantially the same as, or an integral multiple of, a periodicity of the array of focussing elements; wherein the array of focussing elements and the array of image strips (100, 200, 300) are arranged such that as the security element is rotated about a second direction, the second direction being the direction perpendicular to the first direction (Lv) and within the focussing element plane, the first set of image strips is displayed via the array of focussing elements at a first viewing angle and the second set of image strips is displayed via the array of focussing elements at a second viewing angle; wherein each of at least a first subset of the image strips of the first set of image strips comprises a first region having a first optically variable effect generating relief structure and a second region having a second optically variable effect generating relief structure, wherein the first optically variable effect generating relief structure differs from the second optically variable effect generating relief structure in at least one of the pitch of the relief structure, the orientation of the relief structure and the size, shape and/or profile of the elements of the relief structure such that the appearances of the first and second regions (110, 120) vary differently as the security element is rotated about the first direction (Lv). an array of focussing elements defining a focussing element plane, each focussing element being adapted to focus light only in a first direction, the focussing elements being arranged in a regular array along the first direction (Lv); an array of image strips (100, 200, 300) overlapping the array of focussing elements, the array of image strips (100, 200, 300) comprising at least a first set of image strips and a second set of image strips, wherein the first and second sets of image strips (100, 200) are interlaced along the first direction (Lv), and wherein the first and second sets of image strips each have a periodicity along the first direction that is substantially the same as, or an integral multiple of, a periodicity of the array of focussing elements; wherein the array of focussing elements and the array of image strips (100, 200, 300) are arranged such that as the security element is rotated about a second direction, the second direction being the direction perpendicular to the first direction (Lv) and within the focussing element plane, the first set of image strips is displayed via the array of focussing elements at a first viewing angle and the second set of image strips is displayed via the array of focussing elements at a second viewing angle; wherein each of at least a first subset of the image strips of the first set of image strips comprises a first region having a first optically variable effect generating relief structure and a second region having a second optically variable effect generating relief structure, wherein the first optically variable effect generating relief structure differs from the second optically variable effect generating relief structure in at least one of the pitch of the relief structure, the orientation of the relief structure and the size, shape and/or profile of the elements of the relief structure such that the appearances of the first and second regions (110, 120) vary differently as the security element is rotated about the first direction (Lv).