A method of determining particle size distribution from dynamic light scattering data, comprising: obtaining measured correlation functions g ( θ 1) to g ( θ n); and solving an equation of the form: g θ 1 ⋯ g θ n = α 1 K θ 1 ⋯ α n K θ n x wherein: g ( θ i) is the measured correlation function for measurement time i, corresponding with a scattering angle θ i, K ( θ i) is the instrument scattering matrix computed for the angle θ i, x is the particle size distribution and α i is the scaling coefficient for measurement time i (with α 1 = 1); the vector x takes the form: [ x 1,..., x N, n 1,..., n n], where x 1 to x N are the scattering intensities corresponding with each size bin, and the terms n 1 to n n are noise intensities corresponding with each of the measurement times or angles; and columns in K are computed as the expected instrument response according to each element in x, with columns in K at indexes according to elements x 1 to x N calculated for each correlator lag-time, τ and angle, θ, and columns at indexes n 1 to n n calculated as a computed noise contribution for each correlator lag-time, τ, at each angle, θ, based on an assumption about the characteristics of the noise; wherein the computed noise contribution is based on the expected instrument response to a large particle of at least 3 microns in diameter in a scattering volume of the instrument; and wherein the computed noise contribution is determined according to: g 1 τ = exp − q i 2 D t τ where: g 1 ( τ) is the instrument-measured field autocorrelation functions at lag time, τ; q is the scattering wave vector ( q = 4 πn 0 λ sin θ i 2); n 0 is the dispersant refractive index; λ is the vacuum wavelength; θ i is the scattering angle; D t is the translational diffusion coefficient ( D t = k B T 3 πηd); k B is the Boltzmann constant; T is the absolute temperature; η is the dispersant viscosity; and d is the assumed large particle hydrodynamic diameter. obtaining measured correlation functions g ( θ 1) to g ( θ n); and solving an equation of the form: g θ 1 ⋯ g θ n = α 1 K θ 1 ⋯ α n K θ n x wherein: g ( θ i) is the measured correlation function for measurement time i, corresponding with a scattering angle θ i, K ( θ i) is the instrument scattering matrix computed for the angle θ i, x is the particle size distribution and α i is the scaling coefficient for measurement time i (with α 1 = 1); the vector x takes the form: [ x 1,..., x N, n 1,..., n n], where x 1 to x N are the scattering intensities corresponding with each size bin, and the terms n 1 to n n are noise intensities corresponding with each of the measurement times or angles; and columns in K are computed as the expected instrument response according to each element in x, with columns in K at indexes according to elements x 1 to x N calculated for each correlator lag-time, τ and angle, θ, and columns at indexes n 1 to n n calculated as a computed noise contribution for each correlator lag-time, τ, at each angle, θ, based on an assumption about the characteristics of the noise; g ( θ i) is the measured correlation function for measurement time i, corresponding with a scattering angle θ i, K ( θ i) is the instrument scattering matrix computed for the angle θ i, x is the particle size distribution and α i is the scaling coefficient for measurement time i (with α 1 = 1); the vector x takes the form: [ x 1,..., x N, n 1,..., n n], where x 1 to x N are the scattering intensities corresponding with each size bin, and the terms n 1 to n n are noise intensities corresponding with each of the measurement times or angles; and columns in K are computed as the expected instrument response according to each element in x, with columns in K at indexes according to elements x 1 to x N calculated for each correlator lag-time, τ and angle, θ, and columns at indexes n 1 to n n calculated as a computed noise contribution for each correlator lag-time, τ, at each angle, θ, based on an assumption about the characteristics of the noise; wherein the computed noise contribution is based on the expected instrument response to a large particle of at least 3 microns in diameter in a scattering volume of the instrument; and wherein the computed noise contribution is determined according to: g 1 τ = exp − q i 2 D t τ where: g 1 ( τ) is the instrument-measured field autocorrelation functions at lag time, τ; q is the scattering wave vector ( q = 4 πn 0 λ sin θ i 2); n 0 is the dispersant refractive index; λ is the vacuum wavelength; θ i is the scattering angle; D t is the translational diffusion coefficient ( D t = k B T 3 πηd); k B is the Boltzmann constant; T is the absolute temperature; η is the dispersant viscosity; and d is the assumed large particle hydrodynamic diameter.