Dimmer only giving 50% output

Troubleshooting
1

I have a problem I’ve just noticed, to do with the dimmer faders on my fresnel channels.

I have some LED fresnels (BeamzPro BTF300Z) that I’ve made custom profiles for. (I run them as two channels, channel one is a standard dimmer, channel two is a mechanical zoom.) I put each fresnel in its own group (1 device in the group) so I can control each fixture separately. But I also put all the fresnels in a fresnel group (4 devices in the group) so I can control them all together. It works well, but the fader for each group only gives you 50% gain or cut. If you just use the fresnel group fader, the lights only go up to 50% output, even though the fader is at 100%. And if you just use the individual fader group, same result - the light only goes up to 50% output. If you use both faders and boost them both to 100% then the light fixture does indeed go up to 100% output. Similarly, bringing each fader down to zero will only bring the fixture down to 50%, you have to use both faders to bring output down to zero.

Some comment or help with this would be appreciated. Is it because I’ve put the same fixture into two groups that each fader only controls 50% of the dimmer range? It was the only way I could work out how to have individual control and also have it as part of a group. Is there a solution to this? Thanks!

2

Hi,

Thanks for the detailed description, it made this easy to pinpoint.

You guessed it right: this is the expected behavior when a fixture belongs to more than one group. In Photon, when a device is in several groups, the value applied to the fixture is the average of the values coming from each group.

In your setup, each fresnel sits in two groups: its own individual group and the fresnel group. So if the individual fader is at 100% and the fresnel group fader is at 0%, the fixture ends up at (100 + 0) / 2 = 50%. That’s why a single fader only covers half of the range, why you need both faders at 100% to reach full output, and both at 0% to get a complete blackout.

The logic behind this is that no group takes priority over another, each group contributes equally to the final value of the fixture.

So with the current behavior, as long as a fixture is in two groups, you do need to combine both faders to cover the full 0 to 100% range. Your point about the ergonomics is well taken though, and it’s useful feedback for a possible future option on how group values are combined.

Thanks again for the detailed report, and don’t hesitate if you have any other questions!