Light Curves with LED Lights

[Gary]

When comparing a string of incandescent lights and LEDs attached to my Lynx Express and using Vixen's Dimming Curve and Test Console features, I'm not having much luck getting nice fades. Specifically, when I have the LED set at 1 out of 255, its light output is comparable to 40 out of 255 on my incandescent string.

What am I doing wrong? The Lynx Express Utility doesn't seem to make a difference. Does the Dimming Curve feature in Vixen override the settings by the Lynx Express Configuration Utility?

[rrowan]

Hi Gary,

You should see differences.

Did you follow the steps in the wiki?

Using the LE Utility:
Assign the channels per whats connect to it (led,etc)

Put your Express in prg mode by hitting the mode button and when "PRG" shows up hit the edit button to turn the decimal on the right on. It should show "PRG."

Now hit the Program button and the express should program and reboot.

Stop and exit the Utility and test the lights dimming with the software of your choice

Cheers

Rick R.

[Dennis Cherry]

My experiences with LED's dimming is you need to reduce the maximum intensity.  Try using 0-75% or 0-175 in DMX.

For 2 years I could not figure out why the LED's in my display would not look as good as in the software visualizer.

Last year took a sequence and limited the on intensity to 70%, also on the ramps, shimmer, and fade.  What a difference it made. Especially my LED Bethlehem Star.

This year all my LED strings will be limited to 70% max intensity.

Will not use light curves just yet just the maximum intensity.

[Gary]

Hi Gary,

You should see differences.

Did you follow the steps in the wiki?

Using the LE Utility:
Assign the channels per whats connect to it (led,etc)

Put your Express in prg mode by hitting the mode button and when "PRG" shows up hit the edit button to turn the decimal on the right on. It should show "PRG."

Now hit the Program button and the express should program and reboot.

Stop and exit the Utility and test the lights dimming with the software of your choice

Cheers

Rick R.

I followed the steps in the Wiki for assembling the Express.

As for the "reboot", what's supposed to happen? Is the LED display supposed to say "Lynx Express 60 Hz" like it does after you unplug and replug the unit? That doesn't happen now.

[Gary]

I should also ask what the LEDs on the Express Controllers are supposed to do during the Transmitting process. When you start it, LEDs 1-5 flash momentarily, and a second later all the 1-16 channel LEDs turn off, and then mostly the even colored channels flicker.

I have 4 controllers and they act a bit differently after programming before you click the Stop button:

Channels 1-16 has LEDs 1-3 stay on solid. The evened numbered ones on 4-16 are mostly on with a bit of flicker. 5 stays off. The odds 7-15 are mostly off but flicker.

Channels 17-32. Even numbered LEDs 2-16 mostly on but flicker a bit.  1, 3, and 5 mostly dim but flicker a bit.

Channels 33-48. All even numbered channels mosly on but flicker. All odd LEDs are off.

Channels 49-64. Same as 33-48.



I tried changing light curves on all the controllers and the end result is the same... sucky fades. Fading does work... it's just that the light output change when you go from from level 1 to 0 (on a scale of 0-255) doesn't match a regular incandescent.

Thing is, when I go into File | Channel Dimming Curves in Vixen, and play around with that, setting light output at 1 on my LED string looks like 40 on my incandescent string with no light curves programmed.

[RJ]

Hi Gary,

You should see differences.

Did you follow the steps in the wiki?

Using the LE Utility:
Assign the channels per whats connect to it (led,etc)

Put your Express in prg mode by hitting the mode button and when "PRG" shows up hit the edit button to turn the decimal on the right on. It should show "PRG."

Now hit the Program button and the express should program and reboot.

Stop and exit the Utility and test the lights dimming with the software of your choice

Cheers

Rick R.

I followed the steps in the Wiki for assembling the Express.

As for the "reboot", what's supposed to happen? Is the LED display supposed to say "Lynx Express 60 Hz" like it does after you unplug and replug the unit? That doesn't happen now.

No the startup banner does not run but on cold boots.

The 1 - 5 leds should flash very fast in order then the lights all dance to the data of the curve being transmitted from the utility after it restarts which is about a second after the 1-5 flash. You know it rebooted because the channel display will come back up with your start channel or in other words it exits prg mode.

RJ

[RJ]

I should also ask what the LEDs on the Express Controllers are supposed to do during the Transmitting process. When you start it, LEDs 1-5 flash momentarily, and a second later all the 1-16 channel LEDs turn off, and then mostly the even colored channels flicker.

I have 4 controllers and they act a bit differently after programming before you click the Stop button:

Channels 1-16 has LEDs 1-3 stay on solid. The evened numbered ones on 4-16 are mostly on with a bit of flicker. 5 stays off. The odds 7-15 are mostly off but flicker.

Channels 17-32. Even numbered LEDs 2-16 mostly on but flicker a bit.  1, 3, and 5 mostly dim but flicker a bit.

Channels 33-48. All even numbered channels mosly on but flicker. All odd LEDs are off.

Channels 49-64. Same as 33-48.



I tried changing light curves on all the controllers and the end result is the same... sucky fades. Fading does work... it's just that the light output change when you go from from level 1 to 0 (on a scale of 0-255) doesn't match a regular incandescent.

Thing is, when I go into File | Channel Dimming Curves in Vixen, and play around with that, setting light output at 1 on my LED string looks like 40 on my incandescent string with no light curves programmed.

Gary,

First problem is you can not use vixen software curve and the hardware curves together. It is one or the others. I will not go into the benifit of the LNT over the software here but you must choose one to use and only use it. The software was an attempt to give none Lynx equipment the benifits of LNT.

If you go with the LNT then you must use the correct light curve for your lights. You use the LE utility to set your start channel and then populate the 4 curves with either all the same with you lights if you use only one type on that controller or up to four different types. Then on the 16 drop downs below that list channel 1 - 16 drop them down and choose which of the four curves above you want that channel to use. ( what lights will be hooked to that channel).

Now put your LE in prg mode and hit the transmit button in the software. Once the LE flashes and reboots hit stop on the software and you are ready to try the new curves out. Plug the correct string into the correct channel and you should see an improvement in the dimming.

RJ

[Gary]

Hmmm... how do I know if the Lynx Express is using the Light Curves from the Utility or the Light Curves from Vixen? I guess I would be able to know for sure if I could turn off Vixen's Dimming Curves but can't find the option in any menu.  I'm using version 2.5.0.8. Is this question even in the right forum now?

[Gary]

Anyone?

[RJ]

I'm sorry but not able to help on this as I have not used vixen past ver 2.1    Version 2.5 was buggy so most of us stayed at 2.1. I have no need for lowering the resolution of my controllers to get curves since I can get both full 8 bit resolution and matched curves with LNT so I have never used vixen for curves.

I would imagine leaving it set to the default leaves the curves alone. I have never had anyone have this issue before.

RJ

[Gary]

That's odd, I went to You are not allowed to view links. Register or Login, and it indicated that the newest version is 2.1.1.0. My desktop PC has 2.1.4.0 on it, which I downloaded last December to experiment with before I even got my first Express kit, and my old laptop which will be used for my actual Christmas display has 2.5.0.8.

Did vixenlights.com realize that 2.5 was "Vixen Vista" so they reverted back to an older version which was more stable?

Either way, I don't think I'll be using the light curves with my LEDs. Sure, doing a slow fade over 5 seconds or so doesn't look right, but if I do a fade over 1 second, it looks fine. I even hooked up all my different brands, types, and colors of LEDs on one channel and to see how it looks... the fades aren't spot on, but I'll live with it.

It's quite possible that there is nothing I can do about the sudden brightness drop-off when going from 1% to 0% because of the way some of the LEDs in the strings are. I guess some models of LEDs are inherently less energy efficient, because on some of my LED sets, the 1% brightness setting looks like 1% on my incandescent set.

Experimenting the fades yesterday, I realized how stepped and choppy fades were at 100 ms event lengths. 50 ms was an improvement, but still some choppiness. Turning it down to 25 ms (yikes!) made it look acceptable. 25 ms is 40 frames per second, so I may change it to 30 or 33 ms (about 30 fps). It would be nice if the Express didn't only have light curves to smooth out fades, but also had something to allow an LED light string to emulate an incandescent bulb's slower light response times. But I may be dreaming.

[rrowan]

KC stated that 2.5 ver was unstable. It works for some but not others. I tried it and had some issues.

The DLA wiki has the direct link to DL all versions of Vixen

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Click on Download Vixen to see them all

Cheers

Rick R.

[Gary]

I ignored the issue for a few months, but noticed the other day that the Express Config Utility does indeed make a difference for my Lynx Expreses... I didn't really notice a difference at the dim end, but rather the difference I noticed is that for some of the Curves, there is a sudden step up in brightness from level 254 to 255 (or 99 to 100%).

RJ, what is the voltage being sent to the light set when the brightness is set to 1 out of 255 on the Default Curve? If I do the math, it's 120V/255=0.47V. What is the minimum Voltage that the Express can put out? I'd like to know what is involved in creating my own light curves? Looking at the XML file, it doesn't seem to be very DIY-ish.   

[RJ]

This might help you understand.

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You can not calculate the voltages that way for a number of reasons the biggest one being we are not slicing DC power into pieces but a AC sine wave that at any given time is a different amount of change for the next step.

The curves make a difference for mine and the others who have used them and demoed them at minis and such so not sure why you are having such a hard time with them. Are you useing the exact string type with the curve or just trying different curves?

I think there is a couple of nice videos post by users showing the difference on there systems.


RJ