dominicgross Posted September 28, 2003 Share Posted September 28, 2003 hey guys, I need some recomendations for projects for our theatre. The distance from hanging point to stage is about 6-7 meters. Obviously it needs to be bright enough to cut through a 1.2K rig. How is the best way to do it? It will need to run computer stuff and some live video, is this best done with a vision mixer?? What is the longest run for the required cable? cheer people. Link to comment Share on other sites More sharing options...
owen_mcauley Posted September 28, 2003 Share Posted September 28, 2003 More info will be needed at this point, to give you specific help Size of screen/projected imageDistance from lens to centre point of screen/surface to be projected onAngle between screen/surface to be projected onto and projectorColour and material of screen/surface to be projected onQuality of image requiredType of image including colour and contrast Distance from computer to projector for communication method. Blackout requirements for video images??? Mixing between sources etc? Think that's it Owen Link to comment Share on other sites More sharing options...
dominicgross Posted September 28, 2003 Author Share Posted September 28, 2003 okay... Screen will be the cyc at rear of the stage (white cloth) or a gauze hanging mid stage - both about 12x7m (ish). Distance can be anything from 6-8 meters. Angle can be anything from strait on to 90deg Image quality needs to be good (DVD projection) Computer to projector will be about 15m max. Video blackout and source mixing required. Link to comment Share on other sites More sharing options...
owen_mcauley Posted September 28, 2003 Share Posted September 28, 2003 will the stage be lit at the time of projection?If so how much will spill to the cyc? Owen Link to comment Share on other sites More sharing options...
Bryson Posted September 28, 2003 Share Posted September 28, 2003 Sadly, mixing from PC to Video is nowhere near as easy as it would seem. To do it properly, you'll need a scan converter...which is an expensive beast. The TV/Video outs from Laptops look reasonably terrible on all the ones I've seen. (Unless someone knows of a good one...? Actually, I need one for that other stupid job I'm doing..) 12 x 7? That's a rather large screen. You'll need something grown-up for that - 5000 lumens or so. If you're planning to change which screen, you'll also need to refocus and rezoom live or use two projectors. Now. For a 12m wide screen from 8 metres, you need a lens with f=0.6/0.7 ish. That is definately not standard hire stock...in fact, I don't know of any lenses that wide. They're an expensive, specialist thing. From 6 metres you'll need f=0.5. Which is even worse. Lenses that wide are almost all fixed focus, so you won't be able to zoom, so again, you'll need two projectors. Overall, what I'm trying to say is: It's a rather expensive thing to try and do. Best thing would be to: Get the director to accept that you can't fade from Video to PC, accept a cut or an intermediate blackout.Get the director to accept that the image won't fill the screen.Get the director to decide on one (and one only) projection surface. If you can do that, you'll be ok. (Well, you'll still need a big fat projector and an expensive lens, but still...) If you can't do that, then you've just gained almost all of my problems. Only I have 4 of 'em... Link to comment Share on other sites More sharing options...
Big Dave Posted September 29, 2003 Share Posted September 29, 2003 The shortest manufactured lens is 0.8 : 1 which is available my near every manufacturer. Has 2 really big problems though: 1. You loose about 20% of the light output of the projector2. when using cheap 0.8 : 1 lens on LCD projectors, it is often not possible to get a sharp focus across the entire image (cheap is defined as lens costing approx £1000 - £1500) Barco do make projectors with smooth internal switching (can't remember the model number but it's the replacement for the 6000 Series) which may be of use but I don't think it was that cheap.Alternatively, Sanyo XF series LCD's will be perfect for what you want but you'll need external switching. Have a look atAnalogway, they do some interesting switching devices that will do exactly what you want. Link to comment Share on other sites More sharing options...
Bryson Posted September 29, 2003 Share Posted September 29, 2003 Thanks Dave - That's the shortest I've ever seen, but didn't know if they made 'em wider to special order or something. So they don't....so you'll need more throw distance or a smaller screen size. Link to comment Share on other sites More sharing options...
Tom Baldwin Posted September 29, 2003 Share Posted September 29, 2003 Dominic, did you really say you wanted to project onto a gauze? I ask only because, as well all know, a gauze is simply a large collection of holes which are hanging on to some string for dear life, and as such it's not something that tends to reflect all that much light, especially if you hit it straight on - certainly in comparison with a good cyc, or better still a proper projection screen. You may not need the brightness, though, for your application... To overcome the wide image/ short throw problem, you could tile 4 projectors together. Barco have image processing kit which does this very nicely, with faded seams between projectors (rather than stright cuts), which helps blend the four images into a seamless whole. Tom Link to comment Share on other sites More sharing options...
owen_mcauley Posted September 29, 2003 Share Posted September 29, 2003 I have a scan convertor, which can be borrowed/bought for reasonable money if you need, it's a pcmcia card made by realvision, it's a noteTV Pro, I think, (discontinued item from maplins) and will handle resolution of up to 1600 x 1200 on s-video and composite, and looks pretty good, unfortunately my laptop will only output 800 x 600, but powerpoint shows actually look quite good off it! Link to comment Share on other sites More sharing options...
dominicgross Posted February 9, 2004 Author Share Posted February 9, 2004 following on from all this, is their an easy way to work out how powerfull a projector I will need to cut though the 1.2K rig. At the moment we have a slide projector which is a kodak mutent which cuts in quite well... im not sure what power it is. So guys. will 2500 lumen be enough? - bear in mind it will be used mostly during DBO's but also during scenes, with as above, a 1.2K rig up. Cheers. Link to comment Share on other sites More sharing options...
Matt Posted February 9, 2004 Share Posted February 9, 2004 I think we have a 3500 lumen projector, but I am not sure, I'll have a look into it for you. I know it cuts through our parcans (1k x 10) but only just Link to comment Share on other sites More sharing options...
peter Posted February 9, 2004 Share Posted February 9, 2004 This really depends on your focus. If you've got 10k of Parcans focussed onto the projection screen, of course you're not going to see the projection. If you can keep to side/top light then you should be alright with a 2000+ lumen projector. Also watch where you project from in relation to the lighting - I was involved in one projection where every scene had a lovely shadow of a projector in it, whenever the followspots were used. No-one thought to rig the followspots and projector on a different line of sight to the stage. You live and learn though. If you have access to the 2500lumen projector, give it a try. Also, when plotting the show, make sure you put up the projections that will be running at the time, and if needs be, take the lighting state down a little. Link to comment Share on other sites More sharing options...
dominicgross Posted February 9, 2004 Author Share Posted February 9, 2004 cheers for that guys: next thing, is there a toy that excists that works like a shutter in front of the lense to create a proper blackout? I was thinking of doing somthing with a motor, chip and some fibre board, but I think that the 20 meter cable run might be a bit of a problem? cheers Link to comment Share on other sites More sharing options...
peter Posted February 9, 2004 Share Posted February 9, 2004 There was a topic on here a while ago that linked to a DMX widget thingy that went in front of a projector to give a complete blackout. If you do a search it might come up. Link to comment Share on other sites More sharing options...
Peter Russell Posted February 9, 2004 Share Posted February 9, 2004 This has been asked and answered before HereAlthough it seems that the website is down. Note to all, the search engine is your friend, Seek and yee shall find... ;) HTH Peter Link to comment Share on other sites More sharing options...
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