Jane Posted November 9, 2004 Share Posted November 9, 2004 Does anyone know of anyone who makes a DMX controlled blackout system for video projection? Everyone I've spoken to says "use a scroller and neutral density". But it's 2004! How can no-one have invented such a thing! :) Link to comment Share on other sites More sharing options...
Andrew C Posted November 9, 2004 Share Posted November 9, 2004 At the risk of being shouted at for saying "Me Too"; Me too! Running "Oh What A Lovely War" off a laptop & Sony data projector, and am using a flap of cardboard. Link to comment Share on other sites More sharing options...
SimonW Posted November 9, 2004 Share Posted November 9, 2004 What's worked well for me in the past (and seems to work for those venues I'veintroduced to it!) is using an old computer CD drive. If you strip the drive down, removing all of the components (head, etc) except for thedrive tray and motor, and then connect a 5V DC power supply to the motor viaa polarity reversing switch, you can easily open and close the tray from the comfort of you control room. A small bit of black card over the hole in the tray, and viola - one projector blackout that doesn't require you to loose a scroller, or play with ropes and pulleys. Only thing to remember - make sure that you turn the motor off after opening/closing the shutter, otherwise you'll burn it out. Cheers, Simon. Link to comment Share on other sites More sharing options...
MikeR Posted November 9, 2004 Share Posted November 9, 2004 Don't the projectors your using have blackout shutters installed & controlloble from either the IR remote or whatever switchgear youre running? Failing shutters you may find a "pause " button on the handset whihc generally has the same function - though generally not achieved my means of a hardware shutter. Link to comment Share on other sites More sharing options...
Andrew C Posted November 9, 2004 Share Posted November 9, 2004 Using standard LCD projectors. Not seen one that emits "nothing" with a black input. Anyway, the projector is nowhere near the op in this case and the IR reciever is on the back which is against the wall. Nice idea though. Link to comment Share on other sites More sharing options...
computer Posted November 9, 2004 Share Posted November 9, 2004 I've used the old cd tray trick before, 'xcept we used the built in stop/start system with the microswitches inside. basic idea was that we powered it with 12/5v (I had a power supply somewhere which pluggs in and sends out +5v, +12v -12v and GND for testing pc parts and stuff, put it on a molex and soldered a wire to the eject button, so it worked itself, one press to open or close. would be pretty cool to dmxefy it by creating an analogue input for it and running it off a demux. Link to comment Share on other sites More sharing options...
MikeR Posted November 9, 2004 Share Posted November 9, 2004 Projectors are rarely near the operator but usually you can hardwire the infra red remote to the projector, (usually a 2.5mm jack at either end - you definitly can with Barco) I wasnt suggesting a black input or a black level signal from the switchgear - some projectors can be mechanically controlled from switchgear so as to extinguish the lamp or in other cases bring into place hardware shutters (again Barco models have hardware shutters built in for just this purpose). If by standard lcds youre referring to the wee toaster style of projector then as far as Im aware such devices don't exist alas and youre stuck with a cunning Heath Robinson solution. Link to comment Share on other sites More sharing options...
Tom Posted November 10, 2004 Share Posted November 10, 2004 At the ICA they have a DMX shutter for their projectors. I think it's something they made up themselves using some sort of DMX controlled motor with a flag on it. Link to comment Share on other sites More sharing options...
slim_mcslim Posted November 10, 2004 Share Posted November 10, 2004 Well there is no DMX shutter for projectors as there is no real market for one... (in a commercial world) the barco 6 series projectors have electronic shutters operable from the remote control, but they are an optional extra on the base spec of the projector... however I have an idea... most projectors do have a "blank" or "no show" option, equally most projectors have some form of serial rs-232 control to control all the functions of the remote, now some clever person (and I know there are a few on this forum) could build some data interface from DMX to rs232 - just a matter of converting a DMX channel/intensity to a hex address and feeding it to the projector, or the other thing that lighting desks seem to do is talk midi - which is a form of rs232 is it not ( I prepare to stand corrected if thats not the case) so there must be a way of using the little used midi out of the lx desk - to lcd projector et voila from the light shall come darkness... paul... Link to comment Share on other sites More sharing options...
MikeR Posted November 10, 2004 Share Posted November 10, 2004 There are a range of (Extron & Barco) boxes that will communicate with projectors via rs232 - I alluded to them in my initial post in this thread. However the issue being achieving this control from a lighting desk Im not convinced that it's something that anyone would reasonably want to produce as anything other than a get out of jail box so to speak. Surely you use the boxes to do a job that theyre intended for. While it might be nice to have the Barco supply me with coffee throughout a show I dont expect it to do so though I could rig up a can on the lamp to do the basic heating. Link to comment Share on other sites More sharing options...
henny Posted November 10, 2004 Share Posted November 10, 2004 see http://www.milinst.com/DMX/dmxtext.htm#DMX they sell a card that can drive RC servo's from DMX , all you need to do is add a flag to the arm of the servo then you have a DMX flag. or use the +5V out on the card vire a solid state relay to control the eject button on a cd drive as above henny Link to comment Share on other sites More sharing options...
James C Posted November 10, 2004 Share Posted November 10, 2004 A year or so ago I came across a "Video Blackout Device" (VBOD) being advertised. It was a couple of hundred quid - you got a manual/video sensing flag that closed over your projector lens. It had a proprietary remote, rather than DMX control, but apparently it could also be set to open or close according to whether or not it sensed a video feed passing through it and on to the projector. The Website it was on seems to have disappeared though. The guy who was flogging them was N. Rorke. Don't know if it's worth googling either him or "vbod"? Link to comment Share on other sites More sharing options...
pdrage Posted November 10, 2004 Share Posted November 10, 2004 Surely, this is what you want. DMX control and really simple. At 225 Euros, it might be a bit expensive, but it depends on how often you might use it. http://www.wahlberg.dk/video/shutter-filer/hvidbagrund/DSCF0027-lille.jpg Link to comment Share on other sites More sharing options...
Jane Posted November 10, 2004 Author Share Posted November 10, 2004 That's exactly what I've been looking for, thank you so much! I'm off to phone Denmark now... Jane Link to comment Share on other sites More sharing options...
ocfe Posted November 10, 2004 Share Posted November 10, 2004 I remember seeing some at the RSC a while ago, I think they had Stage Electrics Stickers on them, I'm not sure if this is any help - perhaps it was a custom product. Link to comment Share on other sites More sharing options...
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