Continuity generally refers to ensuring there is consistency from one shot to the next in a film. Often due to the complexity of getting each shot right it is necessary to film parts of the same scene over more than one session. Because of this, it is necessary to ensure that the area and subjects in the film are in the same state when continuing filming as they were when the previous shots were taken. This is for the sake of avoiding continuity errors.
Here's a great example of some continuity errors which have been overlooked: the music video for Bon Jovi's "No Apologies" -
The clips used in the video were filmed during two different concerts, and it appears that care has been taken to avoid showing the changing crowd, which is necessary for the sake of avoiding errors. What obvious things have they slipped up with then?
Jon's jacket and Richie's hat (and guitar).
This wouldn't be much of a problem if the video was designed to be a montage of the band's career or something, but the video is edited in a way to make it look as though they are playing the song through in a single concert - which makes the clothing changes seem unnatural. (I'm would let them off having Richie's guitar change part-way through; it's not uncommon for a guitarist to change instrument during a song so it would be fairly believable, if it wasn't jumping backwards and forwards between the two). Not going to lie though, a hat that randomly disappears and reappears would be pretty cool and I would probably buy one.
As well as having to be careful with costume as we've seen above, there are many other factors we will need to be careful of -
- Weather: As it stands we are likely to be filming most of our clip inside, however it is necessary to ensure that either: all of our filming sessions take place during similar weather conditions, or the weather is hidden (windows are hidden from the shot etc.)
- Clocks: These things are just a nightmare and are probably out to get us. If there is a clock in the room, it has to be hidden, no exceptions. It's much easier than having to keep setting it to the same time during every filming session.
- Set design: The last thing we want is to have a sofa/TV/table etc. move around randomly throughout the clip. Unless it's a ghost film of course - that'd be pretty epic. This point is especially relevant right now as we will be filming before and around Christmas time so we will need to be cautious of Christmas decorations in the home.
- Equipment: We need to use the same camera, with the same settings, for every shot in each scene. This keeps everything at the same resolution as opposed to having the clip randomly go blurry/pixellated/tinted in some shots.
- Outside activities: Another reason to hide the window in the shot... if someone's parked their car outside the window as we film at 10 o'clock, there's a good chance it'll have gone by the time we go back to filming at 3.
- Lighting: This one's really important; even just changing a light bulb in a room to a different kind part-way through filming will make some shots look completely out of place after editing them together.
- Cast members' appearances: As well as the costume point mentioned above, members of the cast can't change their physical appearance e.g. having hair cut etc.. I saw a clip a while back where a temporary tattoo changed from the actor's left arm to their right arm part way into the scene... this needs to be avoided.
- TV: Has to be turned off. For obvious reasons.
So yeah, I think these are most of the main ones, however we will also need to be on the lookout for any other factors which could lead to continuity errors during filming.