How do I set up my HMC150 for an interview shot with background out of focus.

[LampoFilm]

Hi
I will be filming a interview shot in a few days. The room is about 10 feet and another room 16 feet. I want the subjects head in focus with background out of focus. I read about setting up a shot to have the subject 1/3 from the wall, and your camera 2/3 from the subject. If I shoot at 16 feet, it seems that I have to have my subject no further then 8 foot and the background is very little bit out of focus. not much. I really don't want my subject to close to the camera. I adjusted focus and iris , but not getting the result I want. It looks great having the subject closer to the camera, but then I feel distortion might happen. How do you set up an interview shot with your camera if you have to shoot in small rooms. Please share your settings.
Thanks

[VideoMaker]

1. Place the camera and subject as you described.
2. Zoom all the way in.
3. Open the aperture as wide as it will go.
4. Adjust the neutral density setting to get close to the right exposure.
5. Fine tune the exposure with the aperture setting, but keeping it as open as possible.
6. Move the subject forward or backward to get the desired framing.
7. Focus
8. Shoot

These settings (full zoom and wide open aperture) will minimize the depth of field which will cause the background to be out of focus, IF you have enough distance between your subject and the background.