Up to now, all the edits we have looked at have been open-ended edits and the edit will continue until you hit the stop button. Often this is exactly how you would want the system to behave. It is equally possible that you want to re-record one shot into a completed transfer. This is where you would use a three point edit where there is an In point for both recorder and player, and an Out point for one of the transports ( assuming only one recorder at the moment) Any three points will give the Pogle sufficient data to work out the edit.
With an insert edit, video and/or audio is recorded onto a tape that
already has been striped. Striping a tape involves feeding a black
video signal to a recorder and recording the entire length of the tape
in real time. This adds the various control tracks and timecode.
Assemble, on the other hand writes all data (video, audio, control
tracks and timecode). This has the advantage that only the first few
minutes of tape need to be striped. If you try to assemble edit in the
middle of an existing transfer however, the in point will be fine, but
the out point will have a section of tape where there is no control
track or timecode data. You will have a hole in the tape! As a safety
feature, the Pogle will not perform closed edits when it is set to
Assemble.
This is a quite rare thing to do. What happens is that the TK has in and out points AND the VTR has in and out points. In order to make sense of this, the telecine SPEED has to be changed to squeeze or stretch the duration of the film shot into the duration of the tape shot. For more infomation see varispeed editing.