Often it can be very useful to adjust the default pan and tilt position of your fixtures. For instance, if we have some moving head fixtures on the stage floor and we use the standard default, then they will all begin pointing straight up. When we build a position, we might select the fixtures and tilt them down, then pan them as needed. If, when we build the next position, we decide to pan them first, and then tilt them down, we will create two similar but very different positions. When we play back our cues, we will find that the fixtures “flip” between these two positions because they are panned and tilted in the opposite ranges.
A simple way to avoid this mistake is to define a default pan and tilt position for these fixtures prior to building your positions. First, we tilt all the fixtures down then pan them as needed so they are all pointing downstage center. Now we store these pan and tilt values as our default values. Then anytime we are building positions, the fixtures will all begin from this location and we can simply pan and tilt as needed, without having to worry about panning or tilting the wrong way around.
– From Brad Schiller’s upcoming June Feeding the Machines article
