Oh -- guess it's not clear. When you get up, go through left door, and down the hall. At the end on the left, open window to see into target room. Click red button on console (it's just in the middle of hall, with no context or connection to anything) to turn on a green cushion force field. Then go back to start room, right door, elevator, and jump into green force field. Thanks for feedback, right door should probably be locked until player turns on force field.
For the puzzle ring, be sure the solved picture is at same angle as the holosolid (eg, head at 4 o'clock, feet at 10 o'clock)
Level 4 might not be clear enough as well -- let us know how it goes !!