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RC4 Knowledge Base

RC4 LumenDim Cross-Fade Mode with WW/CW LEDs

I. When doing motion picture work and using warm/cool white LED panels, it’s useful to be able to pick color temperatures as a mix of warm and cool

A. Cross-fading between the warm/cool white channels to find the correct color temperature is required

B. The brightness level needs to be set without the mix (color temperature) changing

II. How to put the RC4 LumenDimM2 in cross-fade mode

A. In this case, a LumenRadio CMRX system is being used

B. Restore default settings on the RC4 LumenDimM2

1. Using a small tool like a bent paper clip

2. Hold the Function button

2. Using a second small paper clip, tap the Set A Button

3. Release the Function button

C. The LEDs are now assigned to DMX channels 1 and 2 on the console

D. The default PWM frequency is 5kHz, which means no artifacting at typical video frame rates

E. Lower PWM frequencies often produce visible artifacts on video

1. PWM frequencies can be adjusted 

2. RC4 Magic defaults to 615Hz, which produces artifacting

F. Put the unit on a different DMX channel

1. In this instance, channel 31 is being used

G. Set that channel to 30% (or absolute level 75/255)

1. This level selects the ISL slow curve with smoothing

2. If fast blinking or strobing is desired, the ISL fast curve may be preferred

H. On the RC4 LumenDimM2, tap the Set A button

I. Bring channel 31 down to 0

J. Bring channel 31 to full; the LEDs on Dim A will illuminate

K. The second channel of LEDs is automatically set to channel 32

L. Channel 31 is for the warm LED color temperature, channel 32 is for cool (or the reverse, depending on the wiring of the LEDs)

IV. Putting the RC4 W-device into cross-fade mode

A. Using a small tool like a bent paper clip, hold the Function (Func) button

B. Using a second small paper clip, tap the Set B Button

C. Release the Function button

1. This 2-button process selects the second mode in RC4 Series 3 dimmers, which is cross-fade mode. Repeating this 2-button procedure steps through numerous available modes

D. Channel 31 now sets the mix, i.e. the color temperature

E. Channel 32 now sets overall intensity/brightness for the mix

F. This can also be done on the RC4 LumenDimM4. In that case, 2 pairs operate for separate cross-fades of Dim A/B and Dim C/D.