Room delay

When setting up the edit timings for Film to Tape, the parameter that was adjusted to get the correct film frame at the vtr in point was telecine Runup, but with Tape to Tape, Room delay was adjusted. Why is this?
The answer is that with a telecine, the frame count is just that - a count. It is not timecode and is not an absolute value. The Telecine counter can be set to any number you like and, provided the correct Edit Points are set, the correct film frame will be recorded. This is a fundemental difference to Tape to Tape. Here, the timecode on the tape is an ABSOLUTE number. If the programme start is timecode 1 hour, the corrected tape must also have a programme start at 1 hour. If, for eample, there are 3 frames delay through the room, and the player and recorder were running exactly in sync, the recorder would not "see" any pictures untill timecode 1 hour + 3 frames. It would be possible to get the edit correct by altering the recorder in point ( 1 hour minus 3 frames ) or by altering the numbers for the player settings in the edit setup window - which would have to be altered back when the deck is next to be used as a recorder. Room Delay effectively "slips" the player and recorder positions to make the player "lead" the recorder by the same number of frames delay in the room.