8. Tracking explained

The Vista, like most modern, complex lighting consoles, is a tracking desk. Tracking is used to minimise the amount of extraneous information stored in each cue. It can also make programming and editing much more efficient, as data doesn't need to be repeated.

Basically, tracking works by only storing changes in the information. With each cue, the only information stored is what is different from the previous cue. The lights keep doing what you told them to do, until you tell them to do something else. Let's look at how this might work with a simple example:

The table above shows a simple representation of four cues, using a total of 6 channels.

In Cue 1, channel 1 is on at 50%. There is no information for any of the other channels, so in this case they are all at 0% as they haven't been given any intensity information. 

In Cue 2, channel 1 has no information, so it stays on at 50%. Channel 2 comes in at 60% and channel 3 at 80%. Channels 4 through 6 remain off, as they haven't received any information yet.

In Cue 3, channel 1 stays at 50%, channel 2 moves to 0%, channels 4 and 5 move to 50%, and channel 6 is at 90%.

In Cue 4, channel 1 is still at 50%, channel 2 has no information and so stays at 0%. Channel 3 changes from 80% to 60%. Channel 4 remains at 50%. Channel 5 moves to 75%. Channel 6 moves to 0%. 

In the above example, you can see how tracking reduces the amount of information saved in each cue. As channel 1 remains at the same value between all cues, the lighting desk only needs to store that information once. 

Tracking should pose no problems as you plot your cues, as each time you are simply making the onstage look that you want to make. When it can get tricky is where you are editing cues. When editing cues, you need to consider how changes in one cue will affect the next or subsequent cues, as the changes will track through.

Using our example above, consider what would happen if we introduced a Channel 7. 

In the table above, we see that Cue 1 now includes channel 7 at 60%. There is no other information for channel 7 in any of the other cues, so it would stay at 60% in all of those cues. To take it out of a cue, we would need to give it information in that cue. 

In the table above, channel 7 would stay at 60% in Cue 2, go to 0% in Cue 3, and stay at 0% in Cue 4. When editing with tracking, remember, "if you call it in, call it out."

Cue Only Editing

When editing cues, there is the option to work in Cue Only editing, meaning that your changes with effect the selected cue only. Whether to edit with tracking or cue only will be determined by the needs of the cue and the edit. 

To turn on Cue Only editing, click Tools --> Cue Only Editing. The icon next to the menu item will show red when it is turned on, as shown below (there is no other indicator). You can turn Cue Only editing on or off as desired, but you should always be aware of what mode you are working in.

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