Luke Posted December 22, 2004 Share Posted December 22, 2004 A first, maybe, but the other day I was using my brain. I was trying to figure out how one could create a 'figure of eight' type lighting effect with a Goldenscan or something similar. I know that the pan and tilt are controlled by channels 5 and 6 DMX, and I understand that when you program in, it programs in the intensitys and when a programmed state is brought up, it moves the mirror to the specification. Then it got me thinking. I won't be doing this at all, but if anyone could correct me, please do. My theory is that you set a starting point, and set the other channels (1-4) then add this as a chaser step. Then, move the pan and tilt say a 'visible' metre at a time and then enter that as a step in the chaser. Completing this for the whole 'figure of eight', as long as the intensity for the lamp had been set at 100%, every time the step for the chaser increased from one point to another, you would get a smooth flow between steps and a smooth display on stage. This is probably a long winded method, but it'd work for me, I guess. Any input is great, as usual. Link to comment Share on other sites More sharing options...
DSA Posted December 22, 2004 Share Posted December 22, 2004 You could, but this method would be liable to result in jerky fixture movement. Many modern desks include a function for a figure of eight pattern, and this should enable a smooth effect to be created. (I guess it does what you say automatically, with very small increments for each step - think like differentiation from first principles) However having not used this sort of effect or a Goldenscan before - I could be very wrong... Best Wishes, David Link to comment Share on other sites More sharing options...
gareth Posted December 22, 2004 Share Posted December 22, 2004 Programming it as a pan and tilt chase would give you a very rudimentary figure-8 effect, but as DSA says it would be extremely jerky, and the faster you tried to run it the worse it would look! The way that effects generators on moving light desks work, rather than using sequences of discrete programmed levels, is to apply various waveforms (sine, sawtooth, ramp, step, etc.) to various moving light parameters centering around a base value and with variable amplitude and rate. The way they'd produce a figure-8 effect, for example, is to apply sine waveforms to the pan and tilt values, with the tilt waveform running twice as fast as the pan. Hope that makes sense! Link to comment Share on other sites More sharing options...
DSA Posted December 22, 2004 Share Posted December 22, 2004 That does indeed make sense Gareth - you learn something every day! Quite clever too I must add. Link to comment Share on other sites More sharing options...
Luke Posted December 22, 2004 Author Share Posted December 22, 2004 Programming it as a pan and tilt chase would give you a very rudimentary figure-8 effect, but as DSA says it would be extremely jerky, and the faster you tried to run it the worse it would look! The way that effects generators on moving light desks work, rather than using sequences of discrete programmed levels, is to apply various waveforms (sine, sawtooth, ramp, step, etc.) to various moving light parameters centering around a base value and with variable amplitude and rate. The way they'd produce a figure-8 effect, for example, is to apply sine waveforms to the pan and tilt values, with the tilt waveform running twice as fast as the pan. Hope that makes sense!<{POST_SNAPBACK}> Sorry to sound like a complete novice.. but, I don't get it. Link to comment Share on other sites More sharing options...
gareth Posted December 22, 2004 Share Posted December 22, 2004 Sorry to sound like a complete novice.. but, I don't get it.Which bit in particular don't you get? Tell us what you want explained, and someone can explain it! Link to comment Share on other sites More sharing options...
Luke Posted December 23, 2004 Author Share Posted December 23, 2004 No, wait. I get it now. I re-read your post. So.. how would you be able to program a figure of eight on a desk that doesnt have the features that do it for you? Link to comment Share on other sites More sharing options...
Andrew C Posted December 23, 2004 Share Posted December 23, 2004 As you might have guessed; lots of small steps! Work out what sort of change is going to result in a move in the general direction that you want. Has to be said, it's the only way I've ever worked. I use a couple of ETC desks that don't "handle" movers. :( Link to comment Share on other sites More sharing options...
Pete McCrea Posted December 23, 2004 Share Posted December 23, 2004 The way you said at the start. I've worked on a show where we had to do just that with a theatre job and 4 Mac 918's. It was programmed by altering the Pan and Tilt Channel levels, and with about 30 cues that ran in a chase. It did look a bit cack, but it worked. The Pan and Tilt movements were very jerky and got progressively jerkier the faster it went. Link to comment Share on other sites More sharing options...
paulears Posted December 23, 2004 Share Posted December 23, 2004 a moving mirror looks worse doing this type of stepped chase than a moving head - the extra weight and inertia does smooth out some of the roughness. Uncle Strand have added some shape control over the past few updates, but if you run a 300 rather than a 500 it's a little difficult to use unless you have two monitors, or at least tell the desk there are two - as the shape parameters drop off the bottom of the screen! sorry for going OT Link to comment Share on other sites More sharing options...
Pete McCrea Posted December 23, 2004 Share Posted December 23, 2004 Personally I'd not touch Intlligent fixtures without a Moving Light board again....... Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.