DMX Controlled Projection Screen (do they exist?)

[ben-collins]

Hello,

 

Does anyone know if there are such things as rear projection DMX controlled screens? at the moment we have a free standing rear projection screen with a bit of curtain hanging off the bottom of it!

 

when doing shows we find it very awkward to move the thing from the back to the front of the stage and while its getting moved all the time the frames getting weaker and weaker!

 

Any Ideas?

 

Cheers

 

Ben :)

 

http://sphotos.ak.fbcdn.net/hphotos-ak-snc1/hs260.snc1/10729_1185695646696_1357413414_30771824_7262150_n.jpg

[Jamtastic3]

You can get ones that have a control box on the wall for up and down but haven't heard ones that run DMX.

[Ashley R]

You can get ones that have a control box on the wall for up and down but haven't heard ones that run DMX.

 

Wouldent it be a simple task to add DMX capabilitys to the simple switch that would operate the screen after that was installed?

 

I'm thinking allong the lines of 2ch's of control. one for up, one for down.

[Richard P-W]

The last couple I've used had an RF remote control, very similar to a garage door opener! got the SM to drop it in at the right time.

 

Amusing myself now with the idea of direct fader control over DMX, 0% - screen closed, 100% - fully extended...

[Ynot]

When I first read the topic I thought - as I believe do the other respondents - that you just meant DMX control of the raising/lowering of the screen. That would be relatively easy to do by way of a couple of DMX relays (BUT you'd need to be careful - imagine UP is on DMX 201, DOWN on DMX 202... then you hit "1 thru 250 @ 30" for example to do your lamp check.... )

 

However, on second read, I noticed that you said

to move the thing from the back to the front of the stage

....

Is that what you really mean? ie be able to control via DMX the position of the screen from upstage to downstage..?

Because that is an entirely different ball game and would require tracks, motors and other paraphernalia...

[jonhole]

However, on second read, I noticed that you said

to move the thing from the back to the front of the stage

....

Is that what you really mean? ie be able to control via DMX the position of the screen from upstage to downstage..?

Because that is an entirely different ball game and would require tracks, motors and other paraphernalia...

 

That's what the OP is having to currently do now but he would prefer to be able to 'fly' it out.

[Ynot]

That's what the OP is having to currently do now but he would prefer to be able to 'fly' it out.

Actually, I missed the other pertinent bit in the OP in that it is currently

a free standing rear projection screen

which indicates it's a fixed screen on the frame that he mentions...

 

I think some clarification is needed here, OP...

[Caldair]

First thought: Leave the screen at the back and adjust your projector? I can't tell from the photo if that's a proscenium and front curtain or the whole stage.

 

Everything else costs varying degrees of money. There are, as mentioned above,

these

sort of things, or flying the screen out (up) with motors or pulleys. I wouldn't bother with DMX - all you need is a button or two, which can be run from the sidestage or placed next to the console. Or, y'know, a remote. Adding DMX to it just adds cost that you could spend on other things that are more fun.

[sleah]

I'm thinking allong the lines of 2ch's of control. one for up, one for down.

(BUT you'd need to be careful - imagine UP is on DMX 201, DOWN on DMX 202... then you hit "1 thru 250 @ 30" for example to do your lamp check....

Yup, relays would work but as Ynot has touched upon, you would have to make sure there was no possible way that both could close together, as there would be a ****ing big bang :o :o

It is solved very simply by creating an interlock with additional relays :P

 

Although it may not be what the OP wants, it's worth stressing the point about safety with the above idea in case anyone else decides to try it.... :)

[Robin Pratt]

As others have said, the question here is not "can you?", in theory you can control almost anything with DMX if you can find someone to build the right interface for you. There are for example, people who use DMX switch packs so they can cue the coffee pot to switch on 5 mins before the interval!

 

The question is, is it practical/safe/cost effective? Probably not, motorised screens are widely available, but its brobably better/simpler/cheaper to use a seperate dedicated control system, be it wired or RF, so that there is no possiblity of a screen cue being programmed by mistake and having the screen move while someone is in the way of it.

[LXbydesign]

Well considering that looks like a fast-fold screen anyway - it aint gonna roll up nicely!! - unless you do have a grid and can fly it out, but looks like you dont!!!

 

Your best bet would be to scrap it (use it elsewhere) and get the powers that be to put forward a proposal to have a proper roll screen installed - which can be BP or FP and then can be controlled either by a simple switch, or AMX or DMX.

 

As an afterthought, its highly noted that controlling a screen or any moveable scenery / set by DMX is not a good idea. Its do-able, but highly un-recommended. For your application, a simple remote or swtich off-stage would do the job.

 

We have our houselighting and basic audio / projector / screen controlled through AMX on a wireless tablet, but im currently looking at getting an overide swich put in for the screen in case of system failure. AMX is a brilliant system - but when it goes wrong or goes down, it gets a bit tricky.....

 

(edited for content)

[back_ache]

relays would work <snip you would have to make sure there was no possible way that both could close together

 

The way I used to program motorised screens and curtains is to use two relays, one for power on/off which feed a second for up/down.

 

You cannot rely on any kind of software to prevent both up and down being energised simultaneously.

 

One thing I would do in software though is put a timeout in, this is because it is not uncommon for the end-stop switch to fail on the screen and the motor to keep running till it burns out!

[mac.calder]

There is one big problem with "toggle" relays... it makes automation a biatch. You have no persistence of state, you rely on your software (be it desk, PLC, Room Controller, ...) to know the state of the object. Without a feedback system in place (not really possible with a lighting desk) you would need to initialise the state at each show start and if anyone pulls out the remote, you would have to manually update the state. Up/Down contact closures with either a hardware interlock or an inbuilt software interlock on the device is a much better way.

 

May not be a big deal for this particular project, as it seems putting in this RP screen is more of a "Once it's in, it's in" type exercise, but in a lot of theatrical applications, having to track the state of an object is a real pain in the backside.

 

-OP: if you want to put in a new screen solution, I would suggest front project with a roll-down screen and a pile-wind hoist to lower the screen roller down - so that you can still get the floating screen effect (close main, drop screen down in front of the main), dependent on clearance of course. A rear-project roll-down (apart from generally costing more) will look a bit odd, as it is next to impossible to put a valance on and have it look good.

 

AMX/Crestron/Control4 etc is overkill for this situation. Most screen companies have RF and wired remotes available for a under a hundred dollars, or if you do go with something with a pilewind hoist, there is going to be a motor controller (generally a PLC with a few pretty buttons on the front) which can have additional programming added to drop the screen whilst lowering the hoists and vice versa. Something like Crestron or AMX, whilst being able to do cool things like drop the screens, dim the lights, close the curtains, turn on the projector and select the correct source with a single button press, is going to cost over $2,000 (list) for control hardware plus the money for a programmer (say another $2,000), plus a user interface ($100 for a couple of push buttons up to $4,000 for a nice touch panel), cabling and install another couple of G's...

[ben-collins]

Amusing myself now with the idea of direct fader control over DMX, 0% - screen closed, 100% - fully extended...

 

That would be awesome.

 

Is that what you really mean? ie be able to control via DMX the position of the screen from upstage to downstage..?

Because that is an entirely different ball game and would require tracks, motors and other paraphernalia...

 

No, thats what we have to do now with the free standing screen!

 

That's what the OP is having to currently do now but he would prefer to be able to 'fly' it out.

 

Yep, thats what would be ideal

 

First thought: Leave the screen at the back and adjust your projector? I can't tell from the photo if that's a proscenium and front curtain or the whole stage.

 

The photo is looking from the back of the hall to the stage, the picture shows the screen at the front of the stage in-line with the front curtians. we cannot leave the screen at the back of the stage as we would need to front project it and that would effect the performers. it would be nice to be able to control it via DMX, then we could cue it in on the lighting desk to fly in for show intervals etc..

[stevefez]

That's what the OP is having to currently do now but he would prefer to be able to 'fly' it out.

Yep, thats what would be ideal

So to clarify, do you or do you not have the grid or space to fly it out? If not, really the only solution is a motorised roll screen, controlled by one of the various methods described above.

 

edit: SPAG