Dimming RGB LED PAR lights

[rcr52]

Here is a situation I wasn't expecting. I just recieved 12 new 3W PAR64 RGB cans and tried them out last night. First test was in manual mode. Indeed they are bright and mixed colors produce much less of the "rainbow edge" effect than I expected. On to DasLight control. There are no .ssl files for these units, so I had to create one. These are six channel units, so channel 1 is the master dimmer, 2 thru 4 is RGB, 5 and 6 strobe, mixing and speed controls. The problem surfaced when trying out the master dimmer. With the RGB channels all set at 255, the color is (more or less) white. One would expect that when you lower the master dimmer the color would stay white, gradually decreasing in intensity while maintaining the hue. What actually happens is that the color changes from white to a medium intensity green, then to a low intensity red as the master dimmer is brought down. The reason for this became immediately apparant - the RGB channels all have a differnt range of operation for this particular unit. Blue is off at 50; full on at 200. Red is off at 32, full on at 235. Green off at 40, full on at 210. With these non-congruent ranges, controlling them all via a master channel cannot possibly keep a consistent hue while lowering overall intensity. This is all probably due to these being cheap Chinese imports, but the latest technology and good quality costs real money, so I have no choice but to find a way to work with what I can afford.
So my thought is that there needs to be a way to reset, or scale each of the RBG channels range of operation, at least in terms of what the master channel sees. For example, the master channels range of 0-255 would be scaled to 50-200 for the blue channel. Don't believe a maneuver like this is currently possible in DasLight. Can it be done with Sunlite? Anyone else dealing with this issue and have any recommendations?

[Richard CSL]

what you are refering to is a custom dimmer curve. The problem I see is that the master dimmer is inbuilt into the fixtures. so unless the custom dimmer curve is built in too, you will not be able to dim evenly. and even if you could would the intensities at different points on the curve be the same for all RGB channels.

One possible solution is in the head editor, to create dimmer channels instead of colour channels and then use 0-32 for the red channel as off. then create dimmer slider from 33-255, so on and so forth for all the channels. then when you create a dimming cue they should all start together and dim together.

this would mean no colour tab at the top of the sliders , so all colour picking would have to be done live.

Worth a try anyway.