An optical system for directing light over two dimensions, the optical system including: a light source at least one first dispersive element arranged to receive source light comprising at least one of multiple wavelengths (λ 1 - λ N) from the light source and spatially disperse the multiple wavelengths (λ 1 - λ N); a first steering element arranged to receive, from the first dispersive element, a first light signal including a first range of wavelengths comprising a first plurality of the multiple wavelengths (λ 1 - λ k), less than all of the multiple wavelengths (λ 1 - λ N), and without mechanical movement spatially direct the first plurality of the multiple wavelengths (λ 1 - λ k) across a first projection; and a second steering element (804-M) arranged to receive, from the dispersive element, a second light signal including a second range of wavelengths comprising a second plurality of the multiple wavelengths (λ N-k+1 - λ N), less than all of the multiple wavelengths (λ 1 - λ N) and different from the first plurality of the multiple wavelengths (λ 1 - λ k), and without mechanical movement spatially direct the second plurality of the multiple wavelengths (λ N - k+1 - λ N) across a second projection (812-M); wherein in combination the first projection and the second projection (812-M) extend over two dimensions; wherein the first steering element and the second steering element (804-M) each comprises a second dispersive element (904a, 904b) or a diverging mirror (704, 1004); and wherein the first dispersive element is arranged to disperse source light into the first light signal and the second light signal; characterised in that the light source is arranged to scan through the first range of wavelengths and the second range of wavelengths by tuning, whereby the first and second light signals are steered across the first and second projections (812-1, 812-M), respectively. a light source at least one first dispersive element arranged to receive source light comprising at least one of multiple wavelengths (λ 1 - λ N) from the light source and spatially disperse the multiple wavelengths (λ 1 - λ N); a first steering element arranged to receive, from the first dispersive element, a first light signal including a first range of wavelengths comprising a first plurality of the multiple wavelengths (λ 1 - λ k), less than all of the multiple wavelengths (λ 1 - λ N), and without mechanical movement spatially direct the first plurality of the multiple wavelengths (λ 1 - λ k) across a first projection; and a second steering element (804-M) arranged to receive, from the dispersive element, a second light signal including a second range of wavelengths comprising a second plurality of the multiple wavelengths (λ N-k+1 - λ N), less than all of the multiple wavelengths (λ 1 - λ N) and different from the first plurality of the multiple wavelengths (λ 1 - λ k), and without mechanical movement spatially direct the second plurality of the multiple wavelengths (λ N - k+1 - λ N) across a second projection (812-M); wherein in combination the first projection and the second projection (812-M) extend over two dimensions; wherein the first steering element and the second steering element (804-M) each comprises a second dispersive element (904a, 904b) or a diverging mirror (704, 1004); and wherein the first dispersive element is arranged to disperse source light into the first light signal and the second light signal; characterised in that the light source is arranged to scan through the first range of wavelengths and the second range of wavelengths by tuning, whereby the first and second light signals are steered across the first and second projections (812-1, 812-M), respectively.