"Remove pulldown" option unavailable (grayed-out)

Question

My understanding from reading the scant description in the manual, a user should have the option to select "remove pulldown" when importing from a tape-based device.  I have been testing FCP X by importing HDV material from a Sony HVR-A1U (1080i) and a JVC GY-HD110 (720p, 24fps).  In neither case am I given the "remove pulldown" option.  Am I missing something?  Thanks for any advice.

Answer 1

The short answer follows:
"pulldown" is only applicable if your source material was originally film and then transferred to NTSC 29.97 standard def. video.
The longer answer follows:
Back in the early days of video, film was transferred to video using a device called a film-chain which consisted of a modified film projector which was pointed at a TV camera. A film projector consists of a light source, the film gate (which is where each frame of film is held in place), a mechanism to advance the film through the projector at 24 frames per second (FPS), and a shutter to block the light while the film is advanced. Normal film projectors have either two or three blades so that each frame of film is flashed before the audience's eyes at either 48 or 72 FPS before the film is advanced to the next frame.
NTSC video is interlaced which means that each frame of video consists of two fields and the shutter in the film chain projector is designed so that the film is projected for a duration of 2 fields for one frame, then the film is advanced by one frame and that frame is projected for 3 fields, then 2 fields, then 3 fields. When the film is advanced throught the gate it is literally "pulled down" through the gate at this 2 field / 3 field rate. Thus the term "2-3 (or 3-2) pulldown. This adds 12 fields per second to the video stream which gets us from 24 FPS to 30 FPS.
The shutter is also designed so that the film is not projected during the vertical refresh period of the video camera.
Hope that helps.