patch a light to a top level

two ways, both in Patch (there's a third way in Park, but i think for your case, Patch is the way to go):

- Patch>Attributes, select channel, Proportion 90 Enter
or
- create a curve that has Input 100 = Output 90.
- Patch Attributes, select channel, Curve x Enter

Proportion 90 will evenly distribute the 90% change (so if you set your lights to "50%", they will be outputting 45%).  So will Curve > Input 100 = Output 90.

IF you instead just want to set a "cap" of 90%, but keep other output values normal, use the Curve method and also set Input 90 = Output 90.  That will "flatten" the final 10%, while the rest of output will be normal (50% == 50%).

Proportion 90 will evenly distribute the 90% change (so if you set your lights to "50%", they will be outputting 45%).  So will Curve > Input 100 = Output 90.

IF you instead just want to set a "cap" of 90%, but keep other output values normal, use the Curve method and also set Input 90 = Output 90.  That will "flatten" the final 10%, while the rest of output will be normal (50% == 50%).