LED step up to colour? how to get it smooth

Hi,

Are you setting the colour before they fade up or is the colour changing to the new one in the cue where they fade? If this is the case you can use the Mark function to set the colours on the units before they come up with the intensity.

Dan

Hi Dan

Thanks for your speedy response, we have auto marked the cues, so the colour changes happen on the previous cue.

The problem is when we want to have the LED's fade up/down to/from lower intensity, there is a very stilted fade up/down rather than a smooth transition. 

Is there anything we can do, or is it an issue with the fixtures? We're using Chauvet Slimpar Tri 12 LED lights. 

Ah, I see. I'd have thought if you were getting a smooth fade with the wheel you should also get that from the cue as the calculations are essentially the same.

These units have no intensity control so Eos basically calculates the RGB values based on the colour and the virtual intensity your setting. If you're working with very low intensities you may get some variation in colour as the individual LEDs drop out. The only other comment is that they are only 8 bit, so there are only 255 steps for each colour which isn't a huge amount really you will likely see stepping at lower intensities.

Dan

I am  having exactly the same issue. As we are not using  them above 30% so I put a Curve on the intensity  to go 0-35 = 0%-100% this has helped. Moral of the story less than top of the range LEDs that do not have a theatre mode are not worth using in a theatre show. Will not make this mistake again.

http://www.miltec.org.uk/lighting/LED%20Lighting/LED%20Batten%20%26%20Tapes/MTC-Batten2%2018x%2012w%20RGBW%20LED%20batten.html

Instead of bringing up the intensity master, have you tried leaving the intensity at the level you want, then bringing in the colors? I know, I know it should be the same, but sometimes it helps.

If you are using LED fixtures at very low points and they are 8 bit fixtures you will get this.  One low tech fix for this is to buy ND gel and knock the intensity down with it so you can bring the fixtures up to a higher level and get better fades.  Depending on what application you are using them for you might try a .9 ND and that should give you a bit more head room for fades.

ND = Neutral Density Gel

You may know this already, but LED sources don't naturally dim, especially at the low end. LED do have variable intensities, so any natural looking dimming curve is a result of the fixture's firmware and circuitry smoothing things out. Different manufactures solve the dimming issue in different ways, ranging from highly responsive dimming, a sort of afterburn on going to zero like an incandescent (though many feel like a 2k fresnel and not an HPL), or simply a smoothing from one level to another (think MSpeed on a mover). Some models put cost effectiveness and punch over smooth dimming, making them the right tool if you need a lot of eye candy, but not ideal if you're focus is on what how the light reveals a performer or scenery. 

You may need to study how your fixture emulates smooth dimming. Many of the Chauvets have a mode for the dimming curve, which sometimes can have a DMX control. Sometimes moving a channel in a 0 count can be smoother than a slow fade, especially if a color is coming up from or down to 0. Often parts and auto follows can be your best friend. 

-Josh