The shadow on the surface indicates that the sun is behind Aldrin and to his left. Armstrong says that Aldrin was standing in a shallow crater, and so we should interpret ground shadow information accordingly. We can be reasonably assured of the sunlight direction by examining the terminator on Aldrin's roughly spherical helmet cover and the light falling on the PLSS (backpack).
Fig. 1 is a GIF image reproduced from a conspiracist web site and has been color-enhanced, possibly to emphasize the shadow the conspiracist says should not be there. Fortunately the color enhancement reveals a distinct golden tint. Looking at the reflection in Aldrin's faceplate (Fig. 1, Note D) we can see that the lunar module Eagle is near Aldrin and brightly illuminated.
The golden aluminized Mylar insulation is designed to reflect about 50% of the light falling on it. This is done to reduce the amount of heat the various parts of the spacecraft absorb. Reflecting that much light means that the lunar module is very bright indeed, quite sufficient to cast a shadow, as well as provide the golden-tinted light seen to fall on the suit. The Apollo 11 photography provides other examples of this light spill from the lunar module.
