Assemble editing is so-called because shots are assembled one at a time in sequential order. This is where the concept of "linear" editing comes from - assemble editing only works when shots are added in a strictly linear fashion.
When new footage is recorded onto an analogue video tape, you will notice a section of picture disturbance at the end of the newly-recorded section. Anyone who has used a VHS tape to record TV programs will be familiar with this — at the end of the recording the picture jumps all over the place and goes to "snow" before settling down and any previously-recorded video becomes visible.
Importantly, this only happens at the end of the newly-recorded section — the start of the new video begins tidily and appears as an instant cut from one shot to the next. Therefore it is possible to record as many new sections of video as you like as long as they are all recorded in the correct order and you begin recording each new video clip before the end of the last. At the end of the entire video there will always be a section of unstable video — the idea is to make this well after the end of the main feature (it is common to record a long section of black after the closing shot).
How to Assemble Edit
Assuming your editing equipment is all set up and you have prepared a blank master tape1, you are ready for action.
The First Edit
In your record machine, using the jog/shuttle or other controls, move the record tape to the point where you want to begin recording. Don't start at the very beginning of the tape - record a minute or so of colour bars and/or black first2. Put the machine into record/pause mode, so that as soon as you hit the pause button again it will begin recording. In most machines record/pause mode allows you to see the pictures you are about to record.
In your source machine, shuttle the tape to the start of the clip you wish to add to the edit and pause the tape.
At this point you have both machines in pause mode. Press the pause button on both machines simultaneously — the source tape will play and the record machine will begin recording the pictures. Let both machines run until after you have finished recording the footage you need, then stop both tapes.
The Second Edit
Rewind the record machine to the desired end point of the footage you have just recorded, then place the machine in record/pause mode. Shuttle the source tape to the start of the next clip to be added and put it in pause mode. Release the pause buttons and record the clip.
Keep repeating this process until you have finished the entire edit.
Get the Timing Right
One of the first things you'll notice with most consumer-level VCRs is that this process isn't very accurate — the recording will start slightly before or after the paused position. This is because it takes time for the machines to get up to speed and begin playing/recording after you release the pause button.
In professional machines this isn't usually a problem as the machines have built-in "pre-roll" functions which automatically rewind a few seconds and get the timing right. You may even have the option to set the exact pre-roll time.
On consumer-level machines, you will need to do some experimenting and learn each machine's exact characteristics. You can do this by recording a shot of a stopwatch with 100th/second increments. The time between hitting the record/pause button and the first frame which is actually recorded will tell you what the machine's delay is. You can then compensate for this delay by pausing the machine the appropriate number of frames before (or after) the position you want the recording to begin. Although some machines are less consistent than others, you should be able to achieve accuracy of a few frames on most video machines.
Next Page: Insert Editing
(1) For more information, see how to prepare a tape for recording.
(2) When recording black, make sure it is from a stable source. Don't simply record nothing.