Skip to main content
Electronic Theatre Controls Inc

Moving lights not consistent with XYZ Focus positions

Issue

When applying a XYZ Focus position like for example X Focus, Y Focus and Z Focus = 2 / -1 / 0, my movinglights don't consistently go to the same position on the real stage, however they do in Augment3d.

Explanation of Issue

Movinglights will take the shortest path to a XYZ Focus position. So depending on "from where" the light will have to go to a certain position, the actual output DMX value might vary. Theoretically, it should still result in exactly the same position on stage. However since in reality small offsets in hanging positions (and other factors) accumulate to bigger offsets, the actual focus position might be a little off, depending on throw distance. Augment3d might still show the "correct" spot, since those little Offsets in hanging positions are most likely not 100% accurately entered in the Augment3d drawing.

 

This is because movinglights usually have a Pan range of more than 359°. Most common is a Pan range of 540°, so 1 1/2 complete turns. Some fixtures even offer a bigger Pan range than that. This means that most positions on stage can be reached in multiple ways.

 

Example: In both videos below, all lights starts off from a physical (XYZ) position 1, however with different Pan / Tilt values in Video 1 and 2, as you can see in the images below the videos. Then they all move to the same XYZ Focus position (person in the middle of the runway).

Video 1: The yellow and blue lights seem to travel unnecessarily complicated.

Pos1A_Trim.gif

 

Video 2: All four lights take a more optimal path.

Pos1B_Trim.gif

 

Pan / Tilt and XYZ Focus comparison for start positions:

Pos1A Focus.pngPos1B Focus.png

 

Note: Pan / Tilt Format was used in this example to show the transition in the cues more clearly. Using XYZ Format instead will move the lights in a direct line. The resulting DMX value might still vary however depending on the starting position.

Note 2: An exception is a Focus position directly below a movinglight's hanging position. In this case the Pan / Tilt values will always be "straight down" - usually 50% of it's total range.

 

Solution

The FLIP function found in the Focus Encoder Display area will pan and tilt lights to the same physical (XYZ) position with different Pan and Tilt values. Usually, there are 3 ways for a light to reach the same Focus position:

  1. Tilt direct with minimal Pan
  2. 180° Pan and minimal Tilt
  3. 360° Pan and no Tilt

In the 2nd Video above, the yellow and blue lights were flipped on the start position to improve the travel path to the final position.

 

Flip.png

  • Was this article helpful?