I.   ISL fast curveISL fast curveLEDs do not dim linearly: when dimmed to a linear 50%, they appear only slightly less bright than at 100%.  The level must drop to 25% to appear at half brightness.  To make LEDs appear linear, they must be controlled with the Inverse Square Law curve.  All good quality LED dimmers use this technique.  RC4 […]
Read more »  and ISL slow curveISL slow curveLEDs do not dim linearly: when dimmed to a linear 50%, they appear only slightly less bright than at 100%.  The level must drop to 25% to appear at half brightness.  To make LEDs appear linear, they must be controlled with the Inverse Square Law curve.  All good quality LED dimmers use this technique.  RC4 […]
Read more »s explained on a LumenDimM4

A. The default settings for the LumenDimM4 are DMX channels 1 to 4 with the dimmer curve.

1. ISL slow uses RC4 Digital PersistenceDigital PersistenceDigital Persistence is a feature in all RC4 dimmers.  When used with LED light sources, it emulates the way a traditional tungsten lamp behaves when power is applied and removed.  The filament in those lamps take time to heat up and produce white-hot light output.  Similarly, they take time to cool off and stop producing […]
Read more » to emulate the rise and fall of a halogen lamp

2. A strobe or flash effect can be achieved using ISL fast

II. Setting an ISL fast curve on a LumenDimM4

A. This example uses channel 1

1. Streaming DMX data must be present: the LumenDim device must be paired to an active LumenRadio transmitter, and DMX data must be present at the transmitter input.  DMX channel levels are used to set parameters.

2. Assigning DMX channel and dimmer curvesDimmer curvesAn instrument’s  dimming curve is simply how bright the light is in relation to the level of the associated DMX channel. A good dimmer should be perceived by your eye to be smooth and linear: if you set a light level of 50%, the lamp should appear to be half as bright as it does at 100%. […]
Read more » on Dim A (using the Set A buttonSet A ButtonAll RC4 dimmers have Set buttons for each individual dimmer output. The first button is the Set A button. On a 2-channel device these are Set A and Set B buttons. A 4-channel device adds Set C and Set D. The most common use of the Set button is to assign a DMX channel and […]
Read more ») will change the next three dimmers as well

B. Put channel 1 at 50%

1. That is the level that selects the ISL Fast curve

C. Using a small tool like a bent paper clip, press and release the Set A button

1. TheLumenDimM4 assigns the first DMX channel that is up (channel 1 in this case) to Dim A, channel 2 with Dim B, channel 3 with DimC, and so on

2. This process, using a level of 50%, has changed the settings from ISL Slow (or whatever was previously selected) to ISL Fast

D. Test from the DMX console by changing levels on channels 1 to 4.  Jump quickly between high and low levels to see the immediate responsiveness of the ISL Fast dimmer curve (which does not use RC4 Digital Persistence)

1. Green dimmer output indicators appear near the Set buttons

2. The indicators on the LumenDimM4 turn on and off quickly, showing no decay time to the fade

III .Re-setting to the ISL slow curve

A. This example uses channel 1

1. Changing the dimmer curve on channel 1 will change the next three dimmers as well

B. Put channel 1 at 30%

1. That is the level for the ISL Slow curve

C. Using a small tool like a bent paper clip, press and release (tap) the Set A button

1. TheLumenDimM4 assigns the first DMX channel that is up (channel 1 in this case) to Dim A, channel 2 with Dim B, channel 3 with Dim C, and so on

2. This process, using a level of 30%, has changed the settings from ISL Fast (or whatever was previously selected) to ISL Slow

D. Test from the DMX console by changing levels on channels 1 to 4.  Jump quickly between high and low levels to see the smoothed responsiveness of ISL Slow with RC4 Digital Persistence

E. Green LED indicators will appear next to the Set A to the Set D buttonSet D ButtonAll RC4 dimmers have Set buttons for each individual dimmer output. The fourth button is the Set D button. On a 2-channel device these are Set A and Set B buttons. A 4-channel device adds Set C and Set D. The most common use of the Set button is to assign a DMX channel and […]
Read more »s

1. The lights on the LumenDimM4 turn on and off more slowly, showing the decay time

2. This indicates the ISL slow curve

RC4 Digital Persistence is not a simple linear fade.  It has been carefully engineered to mimic the thermal rise and fall of a conventional halogen bulb.  It tends to rise quickly, but die out slowly with a “tail.”  A range of speeds are available for RC4 Digital Persistence, emulating a range of different conventional lamp sizes.