Visible crew/equipment: (Ep. 2) When The Doctor, Jo, and Dr. Tyler are taken into Omega's palace, in the first shot of the multiple passageways (right before Jo says that it looks like Aladdin's cave) the curved chalk actor's mark is visible on the floor, then we see it again in three following shots. Note that when they're all escorted further inside, just as Dr. Tyler comments about the matter/anti-matter not making sense, Jon Pertwee looks down, presumably to make sure he hits his mark.
Visible crew/equipment: As the energy being moves down the city sidewalk, we see its shadow on the concrete. Right beside that, however, we can also see the distinctly-shaped shadow of the camera. (00:35:00)
When You Get Back to Mars, Are You Going to Get It - S3-E24
Visible crew/equipment: When Tim and Martin are carrying Andromeda to the bedroom and Martin opens the door with his Martian finger, the crewmember actually opening the door can be seen on the hinged side of the door. The crewmember continues to move in that space for about 3 seconds during the scene. (00:10:00)