test these approaches in phantom and in vivo experiments for both cases after the initial scanner camera cross calibration the camera was slightly perturbed on purpose to simulate inaccuracies due to cross calibration errors fig1 a d show the results for the phantom and in vivo experiments here fig1 a shows the reference images fig1 b shows the results for no motion correction fig1 c shows the results for prospective correction alone and fig1 d shows the results for combined prospective and retrospective correction for both cases i e phantom and in vivo not running the prospective motion correction system causes significant artifacts fig1 b which were mostly cleared out if the motion tracking was turned on fig1 c however due to the fact that the cross calibration between scanner frame of reference and camera frame of reference was inaccurate the prospectively motion corrected images showed residual artifacts these artifacts manifested themselves as smearing in the phase encoding direction for the phantom experiments and as double lines ringing artifacts for the in vivo cases these artifacts were mostly removed after the application of entropy based autofocusing fig1 d in this work we presented a system that uses prospective optical motion correction in concert with entropy based retrospective autofocusing to mitigate cross calibration errors using prospective motion correction eliminated largely all gross motion artifacts and thus helped to minimize gaps in k space due to rotational motion the tracking data also allowed us to segment k space in a few segments and helped decreasing the number of motion parameters.