F277W mosaic image of the J0252−0503 quasar field. Overplotted are the two MSA pointings (in blue). The quasar position is depicted as an orange dot, and we highlight the radial boundaries of the four annuli with solid orange lines. This image shows that within some annuli there are gaps not covered by the NIRSpec MSA pointing and/or the NIRCam imaging that are accounted for in our coverage selection function S_R(R).