At right, Sojourner has traveled off the lander's rear ramp and onto the surface of Mars. 3-D glasses are necessary to identify surface detail. The rock Barnacle Bill and the rear ramp is to the left of Sojourner.
The image was taken by the Imager for Mars Pathfinder (IMP) on Sol 3. The IMP is a stereo imaging system with color capability provided by 24 selectable filters -- twelve filters per "eye.