Progress in stellar astrometric imaging in the GC, from seeing limited observations (≈0.4 − 0.5″ FWHM, top left) to AO imaging on 8 − 10 m class telescopes (50 − 60 mas FWHM, ≈300 − 500 μas astrometry (top-right), showing a Lucy-Richardson deconvolved and beam-restored AO image), to current interferometric imagery with GRAVITY/VLTI (bottom panels, 2 × 4 mas FWHM resolution, 30 − 100 μas astrometry). Bottom right: central 0.2″ region centered on Sgr A*(IR) on May 30, 2021 (see Appendix A.2, GRAVITY Collaboration 2022). Over 2021, the central GRAVITY field of view was dominated by four stars (S29, S55, S62, and S300) with K-band magnitudes between 16.7 and 19.2, in addition to variable emission from Sgr A*(IR) itself. The dashed circle indicates the field-of-view of GRAVITY, defined by the Gaussian acceptance profile of the pick-up fibres in the instrument. Comparing in the bottom left panel three such images taken on March 30 (red), May 30 (green), and July 26 (blue), the orbital motions of all four stars are easily seen, topped by the ≈8740 km s⁻¹ velocity of S29 at its pericenter on 2021.41 (R_peri ≈ 100 AU).