Eight identical beams: why a group is not one big fixture

You select eight heads, set zoom to the middle, point them at one spot. On stage: eight perfectly identical beams. Technically correct. It looks cheap, and that is obvious even to someone who has never thought about light.

The cause is not the fixtures or their number. The cause is that the group was used as one big fixture: a single value multiplied eight times. A living picture appears when fixtures in a group do almost the same thing.

Three tools turn sameness into a rig.

Fanning: one value, eight different ones

Fanning spreads a value across the group. Instead of "zoom 50% for everyone" you get "zoom from 30% on the far left to 70% on the far right".

What that buys on stage:

• fanned zoom — beams open from narrow to wide. The rig reads as movement even when nothing moves;
• fanned tilt — beams lie in a staircase instead of a fence of identical sticks;
• fanned pan — a fan, the single most recognisable shape a group of heads can make;
• fanned focus — some beams sharp, some soft. Depth, which identical beams never have.

Two things about fanning are worth understanding before you touch the control.

It is symmetrical. The middle of the rig stays where you put it; the edges spread in both directions. This matters: otherwise every move of the fan control would shift the whole picture, and setting the position first and the spread second would be impossible. First you set the value, then you decide how far it spreads.

It follows patch order, that is, addresses — not the order in which you selected fixtures. Also not a detail: addresses usually run left to right along the truss, so the fan comes out physical. If fanning followed click order, the same group would produce a different fan on every selection, and reproducing yesterday's look would be impossible.

In Flux Lights the "Fan" control appears in the bottom panel when two or more fixtures are selected, and applies to the next move of any fader: dimmer, zoom, focus, wheels. The XY pad fans pan — the fan proper — and leaves tilt common: fanning both axes would turn the rig into a diagonal scatter, and the tilt staircase is made with its own fader.

Palette: colour as a set, not as a value

The second way out of sameness is colour. Not "give everyone one better colour", but handing the group a set.

The same logic applies as for a painter with a limited palette: three or four shades distributed across the rig read as intent. Eight arbitrary colours read as a fault.

What works in practice: two or three neighbouring shades plus one contrasting — three warm and one cold, distributed every other fixture. The ear cannot explain it, the eye recognises it instantly. It is the same logic by which a frame never holds eight equally important objects.

White deserves a separate note. A group on white is the most merciless test of whether your fixtures really are identical. Even one model from different production batches gives a different white, and on stage that shows as banding. The fix is either tint correction (on fixtures that have a green/magenta tint channel) or the honest decision not to put them in one row.

Effect phase: movement, not blinking

The third tool is phase offset. An effect run on a group with no offset moves every fixture in sync: eight heads swinging as one. With phase spread across the rig, the same movement becomes a wave.

On stage that is the difference between "blinking" and "running". The parameter is the same; all that changes is whether the fixtures start together.

There is a subtlety that catches newcomers: phase offset and value fanning are different things, even though both "spread across the rig". Fanning changes the VALUE (each fixture gets its own zoom); phase changes the TIME (each fixture makes the same move, but starts later). They can and should be combined: a wave along the rig whose amplitude also fans out is a complex picture built from two simple controls.

The order this is done in

During a run the following sequence works, and the order matters:

1. select the group and set the base value — the one everything else builds around. No fanning yet;
2. add fanning and find the amount where the rig reads but does not fall apart. Usually less than you expect: 20–30% looks better than 100%;
3. hand out colour as a set, not as a single value;
4. run the effect with phase offset, if you want movement.

The reverse order does not work: a fan tuned against a synchronous effect falls apart once phase is added, and vice versa.

When sameness is right after all

Three cases where eight identical beams are exactly what you need, and fanning would be a mistake.

Wash. Front light on a performer must be even. Any fanning here gives patches on the face, and the camera will notice even if the room does not.

A hit. A sharp flash of the whole rig on a musical accent works precisely through sameness: any spread turns a hit into a rustle.

Diagnostics. When you are looking for the fixture that misbehaves, sameness is a tool: whatever stands out from the rig is what you are looking for.

The rule is simple: fanning belongs where the group portrays volume, and hurts where the group performs a function.