If you are new to adaptive optics (AO) like me, the selection of right hardware can be daunting. Starting with a wavefront sensor - they range in price, resolution, and many options which are not obvious. By practical trial and error I learned something about resolution, which wasn't obvious to me a year ago. The Shack-Hartmann wavefront sensor (WFS) is essentially a camera with a lenslet array instead of an objective. There are sensors with 15x15 lenses, 30x30 and higher. Naively, you might think "the more the better" - we are digital age kids used to get high-res for cheap. However, there is a catch. High-res sensor, say, 30x30 lenslets, divides your photon count by 900 per spot. Roughly speaking, when you image a fluorescent bead (or another point source) by a camera with "normal lens" (not a lenslet array), and your peak intensity is 2000, this makes a very nice, high SNR bead image. However, is you switch to Fourier (pupil) plane and image the wave...
I have no commercial interest in any private company mentioned here, all opinions are my personal.