Apollo 8 Hasselblad image from film magazine 17/C - Lunar Orbit. This photo was used in Figure 2-37 of the Analysis of Apollo 8 Photography and Visual Observations (SP-201), which has the following caption:

Apollo 8 oblique frame 2751, showing location of Apollo 8 frame 2148.

The text of the Analysis refers to the figure as follows:

An isodensity trace of the zero-phase region of Apollo 8 frame 2148 (figs. 2-35 to 2-37) shows that the photometric function increases much more sharply with decreasing phase angle than was previously believed. Lunar reflectivity is about 20 percent higher at zero phase than at a 1.5° phase angle. An approximate curve is shown in figure 2-38; these results are subject to later refinement.