But why would I need to do all that - don't the lights just do the same thing every time?
If only they did! But this is rarely the case. Moving
lights aren’t always completely consistent from
unit to unit - their position, and in particular
their edge focus, may vary, often quite dramatically.
Swap a unit out and you’ve got no reference as
to exactly what the light was doing unless
you’ve documented it in some way. The focus of
conventional lights drifts over time. And
that’s just when the show’s in the same
On tour, things get harder. Conventional lights will
need to be re-focussed. Moving lights rigged in
exactly the same relation to the set will probably be
about right, but positions aren’t always
consistent - particularly front-of-house. If you
don’t have a record of what the light did, how
can you be sure you’ve got it back to the right
And what if you need to change the type of lights
you’re using, perhaps in a new production.
Newer consoles will try to adapt the programming to
older lights, older consoles will need more help. In
either case, you’ll want to be able to check
what you’re doing against how things used to
Plus, even if the lights are in the right place
it’s good to have a record when the director
accuses you of leaving an actor unlit: you can show
that they’re standing in the wrong place!