I recently read in one of the Industry Periodicals about ways to make stage lighting more efficient. One of the points made was to keep optics and dimmer cabinets clean.
(I'm reluctant to cite the source until we've had some discussion.)
Now there are a number of perfectly valid reasons why one should keep a dimmer rack's filters and modules clean, but I've never heard of diminished output as being one of them. So the question is: Can/will dust build-up on a dimmer module (assuming dimmer, phase control) cause overheating to such a degree that it leads to a noticeable voltage drop at the fixture?