0.′87 × 0.′87 PS1 g-band template (left panel), g-band Swope image centered on SN 2018oh taken ∼244 days after B-band maximum brightness (middle panel) and the resulting difference image (right panel). At this time, SN 2018oh had a g-band brightness of 19.93 ± 0.02 mag. The solid and dashed white lines boxes represent the slit length, width, and orientation for the DEIMOS and LRIS observations, respectively (note that the LRIS slit length is much larger than the image). The position of the SN, at the PS1 template (left panel) and the difference image (right panel), is marked with tick marks, while for the science image (middle panel) is at the intersection of the two slits.