Determining optical aberration

A system comprising:

• an optical system comprising an adaptive optical element;
• and
• a processor operably connected to the optical system and configured to perform a method comprising the following steps:
• a) obtaining a first image in which the adaptive optical element is in a first configuration;
• b) obtaining a second image in which the adaptive optical element is in a second configuration, wherein the second configuration is different from the first configuration;
• c) applying a transform to the first image and the second image to produce a transformed first image and a transformed second image;
• d) obtaining a ratio comprising the transformed first image and the transformed second image and determining a pseudo-point spread function (pseudo-PSF) from the ratio;
• and
• e) providing data sampled from the pseudo-PSF to a machine learning algorithm that has been trained to determine an output indicative of aberration coefficients from the data.

A non-transitory computer readable medium storing a computer program comprising instructions which, when the program is executed by a processor, cause the processor to carry out a method comprising the following steps:

• a) obtaining a first image in which the adaptive optical element is in a first configuration;
• b) obtaining a second image in which the adaptive optical element is in a second configuration, wherein the second configuration is different from the first configuration;
• c) applying a transform to the first image and the second image to produce a transformed first image and a transformed second image;
• d) obtaining a ratio comprising the transformed first image and the transformed second image and determining a pseudo-point spread function (pseudo-PSF) from the ratio;
• and
• e) providing data sampled from the pseudo-PSF to a machine learning algorithm that has been trained to determine an output indicative of aberration coefficients from the data.