What brightness do you use?

J

jalder

New member
I was wondering how folks manage power load and pixel count on their controllers versus brightness? I tend to run 100 12v pixel strands on a single output. I?ve lowered the brightness to get to the 110 pixel range when things start to flicker towards the end of the strand. I was wondering if I could get up to 125 pixels if brightness was dialed down, say 50% or lower. Or is it more about voltage drop than dimmer pixels? I?m using an E6804, which has four outputs and 5A fuses on each. Using <75% brightness with 125x 40 milliamp pixels should keep it under 4A on the fuse. The E6804 doesn?t have brightness directly in the web gui, but brightness could be lowered in the Falcon Player channel output filters.

So, do folks dial down brightness to get more pixels per strand or only to only get more pixels per controller/PSU bank (say 8 output per PSU)? PSUs and controllers with 4, 8, or 16 outputs start to sound like a hotdog pack versus hotdog bun problem. I?m sure pixel gurus have found the optimal brightness to get the most out of their PSUs.

Thanks
 
This is a strong opinion (called a rant):

I do NOT use brightness as a way to avoid power injection. The only time I adjust brightness is to balance the capabilities of my props and distance to the viewer. For example, my Candy Canes have open top pixels and are standing next to arches that have the pixels shining through some PEX. I run the arches at 100% and the canes at 35% so that I get even intensity to the viewer 2m away. I also turn down my matrix because 1000 pixels in a tight area creates a bit of a beacon pointed at the viewers. The matrix runs at 40% so it is in line with the window and eve pixels that are right next to is. Beyond that, I use effect brightness to make the effect look good on the yard.

Note that I do power injection every 25 pixels for 5v pixels and every 50 pixels for 12v pixels. My PSUs are designed to drive all props at 100% and I believe it is a mistake to design an undersized power distribution just to avoid power injection. I also fill almost every controller port with 600 - 680 pixels (ok one has 700 pixels) so I get best value per controller port.

End Rant. :)
 
Thanks, the rant is informative. I’ve been buying from HolidayCoro for probably ten years and balancing power and cost seems to be the name of the game. HolidayCoro has gone to a hub and spoke model with long range expansion boards and doesn’t seem to be “into” power injection anymore. So I’m wondering what yours looks like since you seem to leverage it so well. Do you have a fused power distribution board in its own CG1500 box with a PSU? If so, who sells the power distribution board and mounting plate?

Buying more controllers or long range expansion boards is probably straightforward and good for business, but rough on my wallet, so savvy power injection sounds more cost effective.

Thanks
 
Last edited:
For the most part, I use 24v PSUs to drive my 5v pixels. At each injection point I add a 5v buck converter. Each converter has a soft fuse built in so it shuts down if the current goes too high. That keeps the current down on the long wire allowing me to drive 400 pixels on a single 16 awg feed going about 25'. I have PSUs spread around the yard as semi centralized clusters. Two PSUs behind the front tree to drive the canes and arches, one at each end of the house to drive the 2k pixels on the eves. Another on the roof for the snowflakes, etc.

My Mega tree and matrix are the exceptions. Mega Tree has two 5v supplies at its base with eight legs on each PSU going through a distribution system. Matrix has two 5v PSUs driving ten 18 AWG feeds each.
 
Last edited:
Have to agree with Martin 100% on this. I always consider how the prop "looks" to the viewer. That said, unless I'm running pixels in pex, I typically find 30% brightness is what looks good to me. In pex, it's 100%. And I typically power inject all my props even though I know I will most likely will run it at 30%. As previously mentioned high density pixel props can almost get washed out if the brightness is to high.
 
Our numbers vary a bit. High density run at 25%. Non-high density are at 30%. Our pixels in PEX are at 50%.
They all look great!
 
I power inject a lot so that I can run at 100% brightness. Wiring with power injection at both ends of a string, and/or laying out the pixels for 'alternate nodes'.

This is because I run at 100% when the sun is still out.
FPP brightness plug-in lowers the brightness to 30% during the light show.
 
I currently run my 20' mega tree with 10x150 pixels doing 2 runs each (up 75, down 75) at 12v on each port of my SanDevice E-682.
I have it limited at 50% on the controller, mostly because I don't want to bother my neighbors and my neighborhood is already pretty dark and doesn't need to compete with light pollution.
I have it split 5 strands on each power supply at 350w, and its not even sweating. I do not know exactly the wattage of my pixels, but it seems to have high quality 18ga wires.

I have it setup to do power injection at the end of each line, but actually haven't plugged it in as it got no fading, and I have been busy working on some other props.
 
jalder said:
...The E6804 doesn?t have brightness directly in the web gui, but brightness could be lowered in the Falcon Player channel output filters...
Click to expand...

Just curious what firmware version you are using. Not to take away from the good information of any of the previous posts but, the E6804 firmware ver. 5.038 has a global dimmer setting under the output page.
Just like MartinMueller2003 does for his matrix, I use that setting on my megatree set to 50% to balance out the brightness compared to the smaller props that are near by. By using the controller dimmer, I don't
have to worry about different brightness settings within xLights.
 
I will add that the discussion of brightness should also include a discussion of the dynamic range and the colour space. That is, when you reduce brightness using the global "brightness" control, you are actually reducing the dynamic range of the pixel. This is because ws2811 pixels do not have a separate brightness control so the brightness setting is applied by the controller to each pixel. This reduces the number of bits per pixel to eliminate the colours with higher light intensity. For example, for the commonly used brightness setting of 30%, the colour space is reduced from 24 bits per pixel, or 16M colours, to about 18.8 bits per pixel which corresponds to about 456K colours.
 
steve123 said:
I will add that the discussion of brightness should also include a discussion of the dynamic range and the colour space. That is, when you reduce brightness using the global "brightness" control, you are actually reducing the dynamic range of the pixel. This is because ws2811 pixels do not have a separate brightness control so the brightness setting is applied by the controller to each pixel. This reduces the number of bits per pixel to eliminate the colours with higher light intensity. For example, for the commonly used brightness setting of 30%, the colour space is reduced from 24 bits per pixel, or 16M colours, to about 18.8 bits per pixel which corresponds to about 456K colours.
Click to expand...
I wish more people talked about this when it comes to pixels.

The standard ws2811/ws2812 pixels we use are 8bit (256 steps).
1708569998901.png

I highly suggest Martin's comments on planning power and power injection for 100%. That way you have flexibility in brightness and don't need to worry about blowing fuses from increasing the brightness.
But even I lower brightness's to match other props.
  • Bullets ~30%
  • Seeds ~50%
  • Strip ~80%

It would be nice if the cheap pixels we used had a higher bit depth (more than 256) but that's too expensive no one in this hobby would buy them.
 
When I was doing a display I ran a lot of them around 30% or so, depends on the prop. Some ran at 100%, just depends on "the look". I ran most props from 24v power supplies and put DC/DC converters at or around each prop. I designed for 100% brightness just in case.

Now that I am running my lighted floats and everything is about the batteries, I run a max of 30% master brightness on individual pixels and 25% on strips since they are denser and visually brighter because of that.

Mark_M brings up rarely talked about point regarding diminished steps in brightness with master control turned down. However, I don't find that an issue with most props because for me it just never mattered that much to the display, nor to my floats. His point is very valid however if your display requires that much definition in color and brightness.
 
You must log in or register to reply here.
Back
Top