Rock Concert Lighting

[Brian]

I was under the impression that the DMX standard required an XLR5 therefore if it doesn't have XLR5s' then it isn't DMX, It might be 100% compatable with adapters but it can't be called DMX without XLR5's...

Correct, the full spec calls for 5-pin XLRs but as a concession allows other connectors to be use for reason of space. But, these alternate connectors may not be any other sort of XLR.

 

It's worth noting that CAT5 cable works fine for DMX.

[DSA]

Right, I've taken some measurements.

 

The stage area is (between the pros) 9.25m wide. It is 6m deep (between cyc cloth and front of pros, with about another 1.15m strip in front of the pros. The height of the pros. is about 5m (done by counting bricks im afraid!), and the grid is about another half a metre (so 5.5m) above that. For interest, the stage is 0.92m high.

 

I hope those dimensions are enough. By the way, FOH bars are about 7m off ground.

 

I just spoke to the head of drama, and the alarms can be turned off, and they do have a fog machine, although it is a crappy DJ one - I could still use it to some effect thou, I spose - but a hazer is the way forward (only £20, I cant believe it!)

 

Sorry, but what do you mean by a 'backlight colour wash'? Just wash on the cyc?

 

Our lighting stock revolves around the 'selecon' range (older style). We have mini PC's and mini fresnels, and 650W (although fitted with 500W bulbs) profiles.

 

I wondered about getting a bar of 4 Pars and 'flying' it 1m below lx bar, to avoid prob of 'border' - would this work?, and how do I fly the bar?

 

Are floor Pars going to work, or are they just a waste of money??

 

I hope this explains the venue.

David

[Tom Baldwin]

A hazer is going to work better than a smoke machine for allowing beams to be seen in the air. The Neutron XS is a good machine, and (unless you have an insanely large school hall - like 1000 seated capacity or some such) will easily fill the hall in a few minutes.

 

A backlight wash is like any other wash, providing even coverage of an area, but in this case the lights are at the back of the stage (up stage) shining towards the front of the stage (down stage), so the backs of the performers are evenly illuminated. Why? Well, with the hazer, it'll give you a wall of light behind the performers; if you have a 3 colour backlight wash, just chasing it can be pretty effective. Any form of backlighting also tends to add depth to the stage, by making the performers stand out from the backdrop.

 

If you want to hang a bar of 4 (or 6) PARs below an existing lighting bar (and parallel with it) then the easiest way is two long C-hangers (aka double ended hook clamp):

http://cgi.www.doughty-engineering.co.uk/theatre/products/photo/T20710.jpg

(image taken from Doughty website: here. I don't recall ever seeing 1m long ones; Doughty list 600mm as the longest. If that's not enough for you, you may have to tie the border up out of the way. You can probably get away with C hangers which are shorter than the border - it depends on the focus you're aiming for (no pun intended).

 

Floor cans can be useful for changing the balance of the lighting: rather than all the light falling out of the sky (that's light, not lanterns, OK? ;) ) you get more variety in where the light comes from. The shadows on performers' faces can also be quite interesting. With many bands playing, you'll have to go on stage an either refocus them between acts, or at least check that the bass player hasn't tripped over them and knocked them into the wings etc.

 

You also asked whether you can use the Sirius DMX outputs at the same time as it's analogue outputs. You can, and the DMX will echo the analogue channels. Remeber the Sirius 24 can only control 24 channels, and so if you have 4 Betapacks, you've used up all the channels. You can also transmit this control information over DMX, but it won't really help, as you won't have any independent control over it for movers etc. In any case, although it's possible to control movers from a Sirius 24, there are plenty of desks out there which make it much easier.

 

Good luck, and keep asking questions!

 

Tom

[Ike]

If you want to hang a bar of 4 (or 6) PARs below an existing lighting bar (and parallel with it) then the easiest way is two long C-hangers (aka double ended hook clamp):

You could always improvise by using two hook calmps ataches together by studding (threaded bar). this is available from screwfix, B&Q etc in 1m lengths.

[DSA]

thats a good idea! Alternatively I could just use a lighting stand, but that would look a bit untidy.

 

Will those standalone 'disco' effects lights look too 'disco'y', or will they be OK?

 

And can the molefay blinders be placed on top of the speakers, or will they need to be on stands?

 

Someone mentioned that confetti cannons would be good, and I agree, however I am not sure what the schools response would be to pyrotechnics. Anyhow, what would I need to hire, and where from - how much would this be likely to cost? - do I go for the co2 or actual pyros for the confetti. and is it confetti, or glitter I want. How long (and how high) does the confetti fall for?

 

David

 

P.S. Do you leave the hazer running continuously? how much fluid would the lemaitre one use up in 3/4hrs? Will I have to pay for the fluid?

And I dont see the advantage of a DMX interface, if you leave it running!

[James]

I wouldn't recomend a confetti cannon.

 

Large pyro confetti cartrages do a verry similar effect and are much safer..

 

However you WILL be clearing up bits of confetti for the rest of your working life at the venue. Can I recomend streamers instead? much easier to clear up!

 

Anyway, If you leave the hazer running constantly with no controll over it then there is always the possibility you can haze out the whole place inadvertantly leaving you unable to see the stage.

 

RE betapacks and moving lights, With your rig there will be lots of opertunity to stick some of your dimmer channels together to cut down on the number of control channels you need.

 

For example, If you have a pair of red fresnels on dimmer 4 ch 2 from SL and another pair from SR on dimmer 2 ch 6 then on the soft patch on your desk you patch those two channels together giving you a spare chanel for use with moving lights, Do this to enough chanels and you should be able to controll some basic movers from your desk. 6 is probablty the minimum number of channels you need to free up, but I suppose you could do it with 4.

 

Good Luck

[MarcT]

It's worth noting that CAT5 cable works fine for DMX.

Are you sure? I was under the impression that a DMX cable should be screened. CAT5 cable is unscreened.

 

There is (or at least there was) a very good website about DMX512 here, which has details of recommended cables.

DMX512 Online

 

...but it seems to be down at the moment.

 

Regards,

Marc

[gareth]

I was under the impression that the DMX standard required an XLR5 therefore if it doesn't have XLR5s' then it isn't DMX, It might be 100% compatable with adapters but it can't be called DMX without XLR5's...

If you follow the standards to the letter then no, you're right, if it's not 5-pin it's not DMX. But try telling that to the Danes ... ;)

[MarcT]

P.S. Do you leave the hazer running continuously? how much fluid would the lemaitre one use up in 3/4hrs?† Will I have to pay for the fluid?

And I dont see the advantage of a DMX interface, if you leave it running!

 

You could leave the hazer running continuously - depends on the size of the venue. You'll have to experiment to see.

 

The le Maitre Neutron XS is a great little machine - FYI it has a mains on/off and a haze on/off switch. You should not try to control it by interrupting the mains (hence the need for 0-10v control input or DMX module).

 

Position it where someone can control the haze on/off switch, and keep an eye on the fluid level, although you'll gets hundreds of hours from a full bottle.

 

You'll probably have to buy some fluid - discuss with the hire co.

 

There is more info (and an online manual) here:

Le Maitre Neutron XS

 

Have fun!

 

Marc

[Guest lightnix]

If you want to hang a bar of 4 (or 6) PARs below an existing lighting bar (and parallel with it) then the easiest way is two long C-hangers (aka double ended hook clamp):

Or, to us a six-bar as a floor unit, put two normal C-hangers at each end and point them out sideways.

 

I often try to put about a third of the rig on the floor. Not only does it make for more interesting looks, but it also makes the de-rig easier.

 

Don't forget the additional trip hazard, though; keep it tidy and make sure all the cables are securely taped down or covered in (taped down) rubber matting for wide runs of many cables. Mark gangways and safe performance areas clearly with white tape and keep these areas clear of kit.

 

Gareth is right about confetti being messy and streamers being neater. Such effects do not have to be pyrotechnic in nature, there are a number of CO2-fired toys around. Maybe our very own Lincoln can help here.

 

There are hazers around where you can set the level of haze and on/off cycles to maintain a moderate level of fog. If you have a DMX controllable machine, you can run it on a slow chase to maintain a level. A fan helps to quickly disperse fog over a wider area, but is best placed behind the machine, to avoid getting the blades all covered in oil.

 

One trick I've used when only a standard smoke machine is available, is to blast a big cloud of smoke under the stage and let it seep up gently through the cracks. Works a treat.

[DSA]

Unfortunately the stage floor is a 'fixed slab' of permanent something or other ie no cracks!

 

So it could be awkward to run the haze - I could appear onstage now and then, flicking the switch.

 

I expect it would be extraxcted though by our system, so it may NEED to be on continuosly anyway.

 

David

[Brian]

It's worth noting that CAT5 cable works fine for DMX.

Are you sure? I was under the impression that a DMX cable should be screened. CAT5 cable is unscreened.

Have a look at DMX over CAT5 tests for more info.

 

A very interesting line from the conclusions is...

Data obtained from all three of these test sessions confirms that, in most respects, UTP and STP Category 5 cable can be expected to perform at least as well as EIA-485 rated data cable for DMX512 applications.

[tuxlux]

It's worth noting that CAT5 cable works fine for DMX.

Are you sure? I was under the impression that a DMX cable should be screened. CAT5 cable is unscreened.

Have a look at DMX over CAT5 tests for more info.

 

A very interesting line from the conclusions is...

Data obtained from all three of these test sessions confirms that, in most respects, UTP and STP Category 5 cable can be expected to perform at least as well as EIA-485 rated data cable for DMX512 applications.

DMX is balanced line (meaning its signals are relative to each other not ground) therefore theres no reason for it to be screened (AFAIK) - what affects one line affects the other one equally and is cancelled out. Twisted pairs should make the cancellations even better.

[Brian]

Someone mentioned that confetti cannons would be good, and I agree, however I am not sure what the schools response would be to pyrotechnics.  Anyhow, what would I need to hire, and where from - how much would this be likely to cost? - do I go for the co2 or actual pyros for the confetti.  and is it confetti, or glitter I want.  How long (and how high) does the confetti fall for?

David

 

one thing to watch with pyros is the age of the person operating them, until 12th Feb it shouldn't be you.

 

As others have pointed out confetti is a bit of a pain to clear up (beaten only by glitter), chinese confetti or streamers are much easier. To hire a basic pyro system will cost you around £20 for a week.

 

Streamers go up about 6 metres and take around 10 seconds to fall, chinese confetti is about the same (it is a cross between confetti and streamers). Prices are around £14 each for a confetti cartridge, £16 each for chinese confetti and £61 for 12 streamer cartridges.

 

Also note that these must be fired in angled firing pods (they won't fit in standard pods). All info above is for Le Maitre kit (usually the easiest to get).

[Tom Baldwin]

The Neutron is quite a powerful little unit, which nonetheless doesn't seem to use very much fluid at all. I regulary use one in a 300 seater venue, and if it's left running for more than 5 or 10 minutes, we start heading for a whiteout. The good news for you is that the Neutron has a remote control connector. It's a 3 pin XLR, with ground, +ve supply and control input on the pins. The hazer will run when the supply is connected to the control input, so you can make up a lead with a latching switch on one end and an XLR on the other. This will allow you to control the hazer from anywhere, as I expect you will need to turn it on or off.

 

Regarding Lightnix's post about letting smoke seep up through the floor, I've used a similar technique with drum risers; make sure it's got a skirt around it, put the smoke machine under the riser, and the smoke will diffuse quite nicely. My personal preference was to point the smoke machine downstage, and have a fan in front of it blowing the smoke back upstage (past the smoke machine). No idea if it made a difference, but it kept me happy... ;)

 

The molefay blinders could be placed on top of the speaker stack, although you'll need something to support them - like most other lights, you can't just rest them on a surface and have full control over where the beam goes. You can make a simple "floor" stand for them from 3 bits of wood: take a 1' square of 1/2" ply, drill an 11mm hole in the centre of it, and nail a 1' long strip of 1/2" by 1" batten down two opposite sides of the square. You can now bolt the molefay to the piece of wood (on the opposite side to that to which you nailed the battens), and the battens will stop the bolt head underneath the wooden plate causing the plate to wobble. I would probably want to ratchet strap this stand to the speaker stack, though, rather than just resting it there.