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Music Promo - Synchronised Lighting Design

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Sam Featherstone
Music Promo - Synchronised Lighting Design
on Aug 26, 2010 at 1:15:29 pm

Hello all,

I'm involved in pre-production at the moment for a music video and just wanted some thoughts/advice on the lighting design.

Here is a reference video where the lights on stands (ignore the ceiling lights) are flashing in the way that we're hoping to achieve:





To add an extra dimension to the piece, we're hoping to synchronise the lights to the beats of the song and we have a midi file with all that info.

With my limited knowledge of lighting these were my thoughts in terms of controlling them:

I can easily program a MIDI track on my laptop that is linked to the playback track on the day. Each MIDI note would represent one of the lights on the day and we could easily tweak the MIDI on the day too.

I would then connect my laptop to a device that translates MIDI to DMX on/off and dimmer commands, theoretically controlling whatever lights are connected to it (http://www.jpleisure.co.uk/item117.htm).

This is where my knowledge weakens. As I understand, a DMX system works by daisy-chaining all the lights involved using DMX cabling and then assigning each light its own DMX channel.

Am I right in thinking that each light should have its own DMX enabled ballast that controls the light power on and off like this: http://www.arri.de/lighting/europe_asia_australia_africa/ballasts/electroni...

Is another option using something like ARRI's Location Multi-Function ballasts which contain control and power for up to 18 lights?

Finally, are there any issues with quickly turning the lights on and off as per the reference video?

Thanks,


Sam


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Andy Babin
Re: Music Promo - Synchronised Lighting Design
on Aug 27, 2010 at 12:52:45 am

My background is as a theatrical electrician/automated lighting programmer, but most of this stuff applies to both.

You are correct in DMX being a daisy chain format, generally you don't "easily" convert MIDI to DMX, the protocols are designed for two different things. Devices exsist to go from MIDI to DMX but i've never had a good experience with them. The big thing is you cannot fade values in the midi spec. You simply get ON (at whatever value) and OFF, there is no way to do "fade from 0 to 50% over 2 seconds in midi, dmx on the other hand is designed for this specific purpose.)

If you want to sync to MIDI you can use MIDI timecode, it's essentially SMPTE timecode over midi. Most modern light consoles (anything ETC, GrandMA, Wholehog series) can accept midi (or smpte) timecode being output by whatever device of your choosing (when we do this setup we use MIDI Timecode being output by Logic Pro on a macbook)

You can then tell the lightboard to fire cues or lights at specific places in timecode (ex. cue 1 go at 00:01:17:51:20.03) or you can use bump buttons to manually trigger lights. For a simple setup manual control may be easier. but when you start dealing with 24+ conventional lights or anything automated you start to run into issues. Most of the consoles have some sort of "learn" feature where you can feed it timecode and do actions on the console (fire cues, bump buttons) and it will record timecode events automatically.

For control of the lights generally (I have a theatre background here) you use some form of dimmer rack (generally an ETC Sensor Rack). Anything tungsten based light will dim fine, and you can set fluorescents to "non dim mode" in the console/rack where they simply switch on/off without too many issues (you can dim them too with mixed results).
For HMI stuff you will need controllable ballasts. The arri thing you linked won't work on overhead fluorescent light. Arri does make DMX controlled stuff for HMI gear though.

Each set of lights would be controlled by one dimmer, and then you program out your sequence as you see fit. You can have multiple lights on one dimmer (assuming you are under the rated load) but each separate thing you want to control needs it's own dimmer channel. Just make sure you have the ability to power a dimmer rack before you go renting gear.

Quickly turning lights on and off can shorten their lifespan, i've never really had issue with it. A lot of the automated/moving lights have mechanical shutters in them that just block the beam and don't douse the lamp to be safe though.

Feel free to contact me if you have any more questions. I'm currently in the process of programming out a music video with 16 automated lights and about 40 conventional units to timecode.


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