Analyzed field of view. Top: gray-scale infrared images of NGC 6121 (left) and NGC 6397 (right) from the Digital Sky Survey 2. The centers of the clusters (taken from the Baumgardt GC database) are highlighted with a red cross. The blue dashed circles have radii equal to N times the half-light radius, with N = [1, 2] for NGC 6121 and [1, 2, 3, 4, 5] for NGC 6397. The red polygons in each panel highlight the coverage of the NIRISS data. Bottom: gray-scale stacked images of NGC 6121 and NGC 6397 made with the GO-1979 NIRISS data. In all panels, north is up and east is to the left.