Gamma settings

[Santacarl]

Hey All,

I've never messed with gamma settings in the past.  Thought I'd tinker with them and noticed there's a place to set gamma in 2 locations.  One is under dimming curves and one under "Controller Connection-'Set Gamma' ".

Which one takes priority, is it either/or...do they work together?  How to choose which to use? 

Yeah, I know, dumb questions....and I'm late to the 'party' again as usual.  Haha.

Thanks....

[Gilrock]

Its just like brightness.  You can change it in xLights or change the settings in the controller.  The controller connection is going to just push it to the controller whereas the old days you had to do it manually.  Just like brightness if you do it in both places it gets a double correction.  Not sure it matters where you do it but I prefer controller settings because they are more obvious when you look at the controller's webpage.

[Santacarl]

if you do it in both places it gets a double correction. 

Thanks for the response Gil.  That's good to know.

BTW, on another 'note'.  I'm adding moving heads this year.  How goes the progress on the new moving heads model?  I'm in a holding pattern before I begin sequencing until the new model goes 'live'.  So I am curious to follow progress.

[Gilrock]

The progress is always documented here:
https://github.com/xLightsSequencer/xLights/discussions/4260

I've had a few weekends in a row where I'm busy and not able to make progress plus I've spent time working on other xLights issues.  Most of the things left are nice to have's and not a showstopper from it being able to be used immediately.  There has been very little feedback.

[Santacarl]

The progress is always documented here:
https://github.com/xLightsSequencer/xLights/discussions/4260

There has been very little feedback.

I'm a bit surprised but I guess it's a bit early yet.  I've been waiting for the more technically competent to wade in and hopefully post some videos before I venture in too far and get myself in trouble.  Haha

Thanks for the response and link.

[Santacarl]

Just like brightness if you do it in both places it gets a double correction.  Not sure it matters where you do it but I prefer controller settings because they are more obvious when you look at the controller's webpage.

I noticed the default gamma under "Dimming Curves" is set to 1.0 on all my pixels.  Is that 'neutral/flat' or is 0 'neutral/flat'?

So If I set the gamma to 2.2 in the controller area I'm actually pushing a gamma of 3.2 out to my pixels?  Or to get a 'true' 2.2 would I set gamma to 0 in the "Dimming Curve" 'tab'?

[MikeKrebs]

1 is neutral (x=y ie straight line). You can see the dimming curves in the graphs below where you set the value. Try a decimal value and you will see the curve move "left". Use 2.2 and it moves to the right.

Gamma characteristics are represented by the equation y = xγ. At the ideal gamma value of 1.0, y = x; but since each monitor has its own unique gamma characteristics (gamma values), y generally doesn't equal x. The above graph depicts a curve adjusted to the standard Windows gamma value of 2.2. https://www.eizo.com/library/basics/lcd_display_gamma/

For LEDs, the typical values of gamma range between 1.5 and 3. https://electricfiredesign.com/2022/11/14/gamma-correction-for-led-lighting/

[Santacarl]

Thanks for the explanation and links Mike.  I noticed the straight line but I can't tell any difference in it whether gamma is set to 1 or 0.

Just curious about interacting with the controller.  Let's say I set my controllers up manually and don't upload gamma values from XL.  If I set gamma to 2.2 in XL and the actual controller, say Falcon 16v3,  has gamma set on board the controller to 1.0 does the controller value of 1.0 'override' the 2.2 that XL has as a setting and send Gamma value of 1.0 on to the pixel?  Or does the XL Gamma value of 2.2 override the Controller gamma value of 1.0 and send gamma 2.2 on to the pixels?

Hope that question makes sense....just trying to understand how all the different locations for gamma settings interact.

[Gilrock]

It depends.  How are you changing gamma in xlights?  Are you using a dimming curve or are you setting gamma in the controller connection property for the modeL?

[Santacarl]

It depends.  How are you changing gamma in xlights?  Are you using a dimming curve or are you setting gamma in the controller connection property for the modeL?

Hey Gil,

Based on previous posts I plan to take the advice to use the controller connection property for the model.  But I'm open to other ideas if it's preferential.  I just want to make sure I understand how to best get gamma 2.2 at the pixel without 'stealth' settings becoming additive.

[Gilrock]

Then don't do dimming curves in xLights.

[Santacarl]

Then don't do dimming curves in xLights.

Thanks Gil.

One more dumb question.  If I set gamma in the controller section on XL is that so that when you upload to the controller it changes the internal gamma setting on the controller or is it changing the gamma in the .fseq file?

Or said another way; if i Set gamma to 1 in the controller section of XL and don't upload my XL settings to the controller and manually set the gamma to 1 on the F16v3 do I output gamma 1 or gamma 2?  Sorry I'm just a bit confused as to what actually controls the gamma; the F16v3 or XL.

[Gilrock]

Controller section in xLights is only for pushing settings to the controller.  If you don't push the settings that section is basically useless except for maybe defining the channel ranges.  Dimming curves change the data stored in the FSEQ file.  Controller settings change the data right before it's output.  The controller won't have any idea that gamma was applied if its done by a dimming curve so if you set it manually in the controller it can double apply it.  You need to quit manually setting things up in the controller.

[Santacarl]

Controller section in xLights is only for pushing settings to the controller.  If you don't push the settings that section is basically useless except for maybe defining the channel ranges.  Dimming curves change the data stored in the FSEQ file.  Controller settings change the data right before it's output.  The controller won't have any idea that gamma was applied if its done by a dimming curve so if you set it manually in the controller it can double apply it.  You need to quit manually setting things up in the controller.

Ahhhh...Now I get it!

Thanks Gil for taking the time to explain.  That is such a good explanation that it should be in the manual!

[jnealand]

Just an observation.  I never see gamma used except to get a good orange at Halloween time and I have seen several references to just leave it alone except then.  I suspect it is a little like pandora's box.  LOL