Q Light Controller+

Video of the issue I’m having: https://streamable.com/q8ztte

Hello! Relatively new to world of theatre tech, and I’ve hit a snag.

I’m helping set up some lighting for a show at our small local theater. They have a light board, but we’re testing out QLC+ for an upcoming show.

I’ve mostly been able to get things up and running, but we have some weird behavior when we try to add a “fade” to our house lights in QLC+. The lights reduce their intensity in steps, rather than a smooth transition.

The house lights are just standard screw in LED bulbs. Fading seems to work fine for our fancier dimmable lights. Fading also works for the house lights when controlled via the light board instead of a computer. We’re using a cheap DMX to USB cable to connect to the MacBook.

I’ve done some research, but it’s unfortunately a bit over my head. It might have something to do with the frequency of the lights? Or maybe the cheap cable is the issue? (Curious why it would be a problem for the house lights and not the other lights though)

I have tried changing the frequency in the QLC settings to 30hz (both udmx & master frequency), but that didn’t seem to do anything.

Any help is appreciated!

If you open the DMX monitor, can you see the value steps in there too?
If it is unnoticeable, lower the fade time considerably for the test...
Where did you set the fade time? In the scene itself or a chaser?

Thanks for responding!

The transition looks smooth in the DMX monitor (no stepping noticeable in the numbers counting down)
Even on a lower fade time, the steppiness is very noticable. For a very short fade time, it basically steps from full>half>off.
I set the fade time directly on the scene, in the "Fade Out" time.

Can you find out the exact make/model of the light board that works, of the problematic LED bulbs and dimmer that is used to dim the led bulbs?

Does your USB DMX cable support DMX input? in other words, can you switch it to receive DMX and show it in the DMX monitor to see what numbers does the light board output?
If you can switch it to input, then patch it as input in QLC+, enable passthrough, and DMX monitor should show what the light board is outputting.

Jano

"Dimmable" household LEDs are problematic. They are not made to theatrical specifications for dimming.

kenact wrote: ↑Tue Jan 16, 2024 10:07 pm "Dimmable" household LEDs are problematic. They are not made to theatrical specifications for dimming.

That is true but the OP is claiming that his lights are fully controllable using another desk and QLC+ underperforms in combination with his DMX interface.
To me the problem points in the direction of his DMX interface doing weird stuff.

GGGss wrote: ↑Wed Jan 17, 2024 5:27 am That is true but the OP is claiming that his lights are fully controllable using another desk and QLC+ underperforms in combination with his DMX interface.
To me the problem points in the direction of his DMX interface doing weird stuff.

If the DMX interface were doing weird stuff to the house lights, wouldn't it make sense that it would be doing weird stuff to every other fixture? How would the DMX interface single out the house lights?

To the OP, when testing with your lighting board, are you using the same dimming timing? Also, when testing on the board, are you changing anything else? Are the fixtures DMX or are they plugged into a DMX distribution box?

I'd gather they're dimmable LED houshold lightbulbs, controlled via classic incandescent/TRIAC dimmers? These don't work smoothly together in my experience, very strange dimming curve, never ending at the same brightness for a certain dmx level etc.
That doesn't explain what the OP is seeing, and in my few experiments with such bulbs and such a dimmer (this kind of thing) the result was not as pretty as when using conventional bulbs, but definitely not "steppy" ...

EDIT: I forgot to add that im my theater we use such dimmers and LED 100W bulb replacements (38° spots) in the bar/foyer, and control them from a 6 channel manual DMX mixer. They also fade like I described. Rather unstable at the low end, okish between 20 and 60 - 70% where they're almost at full brightness already

Hello!
Had the same issue right this morning! Stuttering in the fade out.
By monitoring the % values I recognized that the "total dimming" values of the blinders in the same channel group were "stuttering", meaning they were going up and down fast during fade out.
How did I configure before:
A scene, with a certain color defined through the channel group, in this case RGBW, plus a "total dimming" value for that specific scene.
This does conflict during fade out.
Resolution: Configuration of the color setting in the scene but without a "total dimming" value.
"Total dimming" for this channel group I then set through the simple workspace. And the respective scene (with fade-in/fade-out time) I activated/de-activated/flash function through a button I created on the virtual console. This has worked out finally but only when setting the total dimming for the channel group separately.

Not sure if this is a bug or feature.
I wanted to have a dance floor blinder with the (pre-defined) maximum light intensity and a simulated fade in/out effect of the "glowing" led blinders. Regardless of the global setting of the total dimming value on that channel group in that moment of time.