CharlieH Posted October 21, 2011 Share Posted October 21, 2011 I know this has been done before (here) but that was all a while ago, and the company mentioned in the first few posts is no longer available. I am lighting designer for an AS production of Punk Rock at school in a few months, and I would really like to fly some fluorescent tubes from the ceiling, as you find in many libraries, as we are doing it Stansialvskian and as far as I can see this would be the best way of making it look naturalistic. Ideally I am after the 'flickering on' effect for when the characters 'turn on' the lights in the library (which of course will be accompanied by a more intense general wash), however I would also like it to be dimmable; so if I fade to a BO mid scene, to show the passing of time maybe, I do not have them all snapping off. My question is are the 2 effects mentioned above mutually exclusive, and if not then what sort of tubes do I need and can they be controlled from a standard theatrical dimmer? I could speak to the school electrician about creating some form of external ballast, but I am already asking him to do a lot for this performance so I would rather avoid this if possible. The next problem is that we have no spare fly bars on stage, so I am going to have to find some new method of suspending the tubes - if anybody has any ideas then they would be greatly appreciated! Thanks everyone,Charlie Link to comment Share on other sites More sharing options...
timsabre Posted October 21, 2011 Share Posted October 21, 2011 Tridonic (linky) make ballast packs for fluoro tubes which have 1-10V analogue input for dimming. They are long thin things, just connect mains and 2 wires to each end of the tube, and It would be a relatively easy job to modify a standard fluorescent fitting.The main problem is they don't turn off completely using the 1-10V signal, you have to cut the power, and when you've cut the power they don't come back on instantly. The 1-10V signal is quite fadey too so you'd have difficulty doing your flicker-on effect. However a standard DMX demux would control them, coupled with a DMX switch pack to turn them completely off. They do DALI ballasts as well but you'd have fun trying to convert a theatrical desk to DALI. Link to comment Share on other sites More sharing options...
photographic08 Posted October 21, 2011 Share Posted October 21, 2011 If you've run out of bars how about having them as up lighting / foot lights along the front on the stage? The fluorescents I had experience with before came in a fitting with a red, green and blue tube in each one. They had an adaptor which got mains power (15a plug I think with a 15 to 16a adaptor) and DMX, and turned it into their own type of connector. Each unit then just linked together with that connector. They have a pretty good dimmer curve, and dont flicker unless you want them to. Without seeing a picture this might be similar. An LED strip-light might be another option, and they are probably easier to get hold of. Link to comment Share on other sites More sharing options...
david.elsbury Posted October 21, 2011 Share Posted October 21, 2011 @photographic08 - I think the fitting you refert o is the Martin Cyclo - http://www.martin.com/product/product.asp?product=cycloseries . I can't see that putting the fixtures on the front edge of the stage will give you the same effect.... If you want them hung, is it possible to dead hang them either from the fly floor, or hang them below existing flybars on wire drifts? Best to chat to the venue and see what they suggest? HTHDavid Link to comment Share on other sites More sharing options...
adam2 Posted October 22, 2011 Share Posted October 22, 2011 Any common type of flourescent tube can be dimmed providing that they are connected to special dimming ballasts.It is the ballasts that are special, not the lamps.Retrofitting dimming ballasts to conventional fittings is easy, subjects to the usuall caveats regarding electrics. Dimming ballasts require either a DC control signal, or a digital signal, they are not normally compatible with a standard dimmer.If only one circuit of flourescent dimming is required, it might be simpler to control this by hand, not via a lighting desk. Link to comment Share on other sites More sharing options...
dbuckley Posted October 22, 2011 Share Posted October 22, 2011 SE Lightmanagement AG now do a version of the VIP90 dimmable ballast with DMX control, so it appears there is really no reason why anyone (in 240V-land, anyway, 110V has its own problems) can complain that fluoros are hard anymore. Other than the language problem. Data sheet in English here Link to comment Share on other sites More sharing options...
c.cam108 Posted October 22, 2011 Share Posted October 22, 2011 However a standard DMX demux would control them, coupled with a DMX switch pack to turn them completely off.That's not true I'm afraid. 1-10v fluorescent control is completely different to 0-10v theatrical dimming. You can run the risk of damaging your desk or ballasts trying this. DMX to 1-10v converters are available but expensive per channel, whereas DMX to DALI converters are much more common and can control many more fittings, as (like DMX) DALI is a multiplexed signal. I would seriously avoid 1-10v as that's what we went for for our house lights and it was a big mistake. Colin C Link to comment Share on other sites More sharing options...
dbuckley Posted October 22, 2011 Share Posted October 22, 2011 And... fluoro ballasts with 0-10V control, the control terminals are often not isolated from the mains - some big risks there. Link to comment Share on other sites More sharing options...
CharlieH Posted October 22, 2011 Author Share Posted October 22, 2011 Thanks to everyone for their replies......That Stage Electrics one looks good form the spec, but might send them an email to get some more info about it. Alternatively LED battens might do the job (once frosted over the front) as they could be dimmed, or programmed to do a random flash to mimic the fluorescent starter tube. It's food for thought! Keep the ideas coming in, and thanks for your help!Charlie Link to comment Share on other sites More sharing options...
neild Posted October 22, 2011 Share Posted October 22, 2011 Have a look at Sparks Theatrical Hire in London. They used to have loads of DMX dimmable flouries. - Used a load of them for a show a few years ago, and we retro fitted them to traditional style office fittings to suit the set. The 'switching on' flicker was achieved with a careful bit of chase plotting. Good Luck, Neil Link to comment Share on other sites More sharing options...
timsabre Posted October 22, 2011 Share Posted October 22, 2011 However a standard DMX demux would control them, coupled with a DMX switch pack to turn them completely off.That's not true I'm afraid. 1-10v fluorescent control is completely different to 0-10v theatrical dimming. You can run the risk of damaging your desk or ballasts trying this.DMX to 1-10v converters are available but expensive per channel, whereas DMX to DALI converters are much more common and can control many more fittings, as (like DMX) DALI is a multiplexed signal.I would seriously avoid 1-10v as that's what we went for for our house lights and it was a big mistake. Um, the Tridonic ballasts I linked to are isolated and are controllable from a standard 0-10V demux, I have done it. You might be right about other brands. But I think the LED idea is actually better anyway. Link to comment Share on other sites More sharing options...
CharlieH Posted October 24, 2011 Author Share Posted October 24, 2011 Just to confirm, Sparks are sorting me out with some tubes. They seem ideal!Thanks to everyone for their help - I appreciate it. Photos will be up in the 'Show Your School Production'; thread once the images have been cleared for release by the exam board!Charlie Link to comment Share on other sites More sharing options...
neild Posted October 25, 2011 Share Posted October 25, 2011 Pleased to hear Sparks sorted you out. They are a really nice company to deal with! Link to comment Share on other sites More sharing options...
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