Stairville LED Par 56

[Philip Dixon]

Hello,

I will be patching some lights into our Solution desk very shortly, and was just wondering what the difference between these two is?

LED Par 56 : No Dimmer
LED Par 56 : Virtual Dimmer

There isn't ant mention of 'virtual dimmer' in the fixture's manual.

Regards,

Philip.

[CPlater1]

Virtual dimmer adds an intensity (dimmer) channel for those fixtures that don't have a specific dimmer channel.  This is useful if you want to dim certain colours etc.

[kgallen]

Hi Philip,

To elaborate on what Chris is saying:

Say you have an (old) fixture that only has Red, Green and Blue control channels in the DMX map (3 DMX channels), then it is tricky to set up a colour then just fade in or out that colour, because you'd have to move the R,G and B channels proportionally to maintain the colour during the intensity fade up and down. Newer fixtures would have R,G,B and Dimmer built into the DMX map (4 DMX channels). Where the fixture does not have Dimmer built in, you can emulate the function on the desk. With your example, the "LED Par 56: Virtual Dimmer" has 4 control channels on the desk, but only 3 of these (the R,G,B) actually go out to the fixture over DMX (just the same as the "LED Par 56: No Dimmer"). The fourth channel - the dimmer (or virtual dimmer) is available on the desk, and the desk does the scaling of the DMX R,G,B values according to the level of the (virtual) dimmer channel on the desk. That way you can fade up and down the brightness of your R,G,B colour just by changing the level of the (virtual) dimmer channel on the desk.

Unless you've got very old (10 years+) or very cheap fixtures it's unusual for them to not have Dimmer built into the DMX map these days.

If you've got some of these...

https://www.thomann.de/gb/stairville_led_par_56_alu_schwarz.htm

...then they don't have an inbuilt dimmer channel, so I'd recommend you use a fixture definition with a virtual dimmer. However this particular product has 5 DMX channels: CH1 is a MODE channel and CH5 is a SPEED channel. CH2-4 are RGB. It would be best to have a profile specifically designed for this fixture to handle the 5 DMX channels, plus add a virtual dimmer. You could get away with the two profiles you list but you will not have control of CH1 and CH5 and you would have to configure the desk to map that fixture to DMX address+1 compared to the address setting on the LED Par (because you want the desk R,G,B channels to line up with CH2,3,4 on the LED Par) and you'd have to make sure you didn't have any other fixture channel overlaying that CH1 and CH5 - i.e. you'd still have to space your addressing at 5 address increments. You wouldn't have control of MODE, but a value of 0 on that channel means you get RGB control and the desk should output a data value of 0 on an unpatched address.

Hope that helps and I didn't over-cook the explanation...

Kevin

ETA: I just looked in the fixture library (release 35) and there is a Stairville -> LED Par 56: Virtual Dimmer in there that defines the 5 real channels (and adds a virtual dimmer). If that was what you were referring to in your opening post, then that's the one to choose!

 

[Philip Dixon]

Kevin,

Thank you for the explanation. I'm not sure how old they are (nobody at this school has "the knowledge"). I'll let you know how we get on when I'm back on site next.

Regards,

 

Philip

 

[Philip Dixon]

Just read this in the manual...

"This device may be used only by persons with sufficient physical, sensorial, and intellectual abilities"

...that's me snookered then.