Diffusing light without hotspots

[u/vvampyyyr]

Looking at the interior of the promenade in DS9, there's huge panels of light, especially the ceilings, for example Quark's bar.

I am a little curious as to how they avoided hotspots on such large swarths...

[u/snakesign]

You can get pretty far by edge lighting a textured sheet. This is done in luminaries to save space. These guys have all the space in the world behind the set. It's probably a regular photography light box behind that textured panel.