A major part of Premier Event Magic is the tense and exciting Final 8, whether it's a PTQ, a Grand Prix or the Pro Tour itself. It's the responsibility of the Judge to make sure that the tension and excitement is not upset by technical difficulties.
As much as is possible, games should be decided by the players' actions within the frame of the game. We don't want players disqualified, most especially in front of the TV cameras, for trivial matters. The Judge's posture isn't different from one Premier Event to the other; treat the Final 8 of a PTQ the same as you would the Pro Tour (save for the obvious difference in Rules Enforcement Level).
There are additional concerns when Judging an event where there are cameras present, such as taking the sleeves off of cards (reflection problems) or making sure the players keep their hands fanned so the audience can see them. The start of games may also be delayed in order to get better TV coverage. The production crew will direct you.
Here are some tips for keeping the game running smoothly and promoting a professional atmosphere.
Ensure technically correct play. If a player is about to make a procedural error (like forgetting to untap or putting a creature in the graveyard if it doesn't have lethal damage), prevent them from doing so. If you're not sure what a player is doing or what Phase/Step he's in, ask him. If something happens and you're unsure of the ruling (even though the players both seem comfortable with what's going on), stop the match and consult the Head Judge, another Judge or a ruling reference.
Adopt a professional attitude. Address and refer to the players by an honorific ("Mr.", "Ms.", "Dr."). Do the same for anyone else you might address (cameramen, spectators). If you don't know their name, use "Sir" or "Ma'am". Refrain from using player slang (such as "jank" or "mise"). Save discussion about games until after the match is completed. If there are cameras on, constantly be aware that anything you and the players say and do can and will be heard and seen. Shake the players' hands before and after the match. Suggest they do the same (although most players already do so). Maintain an air of complete neutrality.
Interrupt the players as little as possible. Let the game flow of its own accord, as long as things are going smoothly. If you need to remind a player of something (like tapping his cards all the way, or announcing what color mana he's getting from his City of Brass), do it when it will cause the least disruption (like between turns or when a player is shuffling). However, if an interruption is warranted (a player makes an illegal play), don't hesitate to stop the game.
Keep score. The DCI makes score sheets; if you don't have access to them, simply create your own. Divide a sheet of paper vertically, writing each player's name at the top of the column. Left-justify their life totals. Whenever a player's life total changes, write down the source of the damage/life loss. At each life change, announce the new life total. If something damages both players simultaneously, announce the name before the score. When a game or the match is over, announce the score (eg"Game 1, Mr. Finkel" or "Game 3 and Match, Mr. Budde"). Write down anything else you deem relevant. This includes, but isn't limited to, which player started the game, if there were any mulligans, and noting when a player plays a land.
Stay focused. Pay attention to the technical aspects of the game. Don't consider what you might do if you were playing; watch what the players are doing. Unless the situation warrants it (eg-if stalling or slow play is an issue), don't study the players' hands. Don't try to think ahead and anticipate what they're going to do, simply pay attention to what they're doing. Refrain from making editorial comments about the game being played. Don't let your mind wander.
Keep winners sequestered. At Pro Tours and Continential Championships, Final 8s are done in closed rooms. Keep winners in the confines of that room (or other specially-designated area). This allows players to focus on their upcoming match instead of answering a group of questions from well-wishers or admirers. It also keeps them from getting any technical advice from friends or teammates. Provide (or have the Tournament Organizer provide) for the player's comfort as much as possible. Even at this point, refrain from discussing the previous match (in all but the most general terms) with the player. Do this to avoid inadvertently giving the player strategic assisstance for later rounds. Keeping winners sequestered may be more difficult at local PTQs. Your specific site situation will determine what you can do and how you can do it.
The rules change when the lights go on. Judges are always responsible for creating and fostering a fair and equitable environment for play. At Premier Events, they're also responsible for making sure the cameras see it.