Re: TRIAC dimmer control spreadsheet; was Re: Controlling Holiday Lights

["Robert L Bass" <robertbass1@xxxxxxxxxxx>]

> But as Robert wrote earlier in the thread, and
> you point out here, dynamic (changing) scenes
> such as those used in theatre and concerts
> need more levels...

True, but since many HA applications also encompass HT design, it's pertinent to the discussion.

> (Note though, that 256 levels are that all the
> great majority of professional theatres and
> other entertainment venues have,  so if 256
> is not enough, the majority of performances
> world wide are unsatisfactory ;-)
>
> I realize now that fade rate may be something
> that is of interest to others in HA, and for that
> purpose, 16 levels may indeed be inadequate
> depending on one's preferences.

Completely agree, Marc.  I should also point out for the sake of others that fade rate is independent of the number of available
dimming steps between ON and OFF.  I recall a *scene* we set up during a Christmas play one year.  The scene called for a single
fixture projecting through a star shaped gobo to create the image of a brilliant star slowly appearing in the "sky".  A Source IV
lamp was programmed to fade from OFF to full on over the course of several minutes.  During the first minute or so it looked like
all the other stars in the background.  As the actors moved about the stage and the scene progressed, the "Christmas Star" slowly
became the most brilliant light in the scene.  It was interesting listening to the ooohs and aaahs as different people noticed what
was happening.

The system stepped the dimmer through 255 levels.  During programming I usually "wrote" the scenes using 5% increments (100% on, 55%
ON, etc.).  Once the scenes for a given performance were blocked in I would go through the script, adjusting each fixture with a
wheel -- paying no attention at all to the actual output levels -- until I got the visual effects I wanted.  Later, after the
scenery and backdrops were done, I'd redo almost every scene -- again using the wheel and paying no attention to levels.

The above is pretty much how all small-scale (and many large scale) lighting designs are done.  I realize that this is borderline
OT, but thought it might be interesting to a few folks anyway.

--

Regards,
Robert L Bass

=============================>
Bass Home Electronics
941-866-1100
4883 Fallcrest Circle
Sarasota · Florida · 34233
http://www.bassburglaralarms.com
=============================>