Video projection onto the back wall of a village hall stage

[bagel]

Hi

I look after the lighting for amateur theatre productions in a small village hall (capacity around 100, seated).

For our next production, our director has asked if we can make use of video to provide static and moving backdrops - I think he has seen the great effect it can have in professional productions, and would like to replicate that!

 

The stage is about 4m wide, 5m deep (from the proscenium to the back wall), and 3.2m from floor to ceiling.

 

The director's vision is to open the rear curtains (which are 1.2m from the back wall), and project directly onto the back wall. It's a flat wall with a few small brackets and things on it, but generally ok. In the past, we've painted backdrops directly onto it, but it's currently white.

 

There is a ceiling-mounted lighting bar 2.3m from the back wall, which currently holds a couple of floods and LEDs for lighting the back curtains (or back wall when the curtains are opened).

 

 

I have no experience whatsoever in video projection, so would really appreciate some guidance!

 

 

Would the best option be to mount the projector on the lighting bar? Or should I mount on its own dedicated bracket fixed to the ceiling?

If I mount it in about this position, would I need a short throw (or maybe ultra short throw) projector as it would be only just over 2m from the back wall?

Will I be able to project an image up to 4m wide by 3m high?

I'm assuming I need it as close as possible to the back wall, so that the actors have as much of the stage as possible to move around in without having the image projected onto them.

 

I will need to use it in conjunction with normal stage lights (fresnels and profile spots), mounted on a bar in front of the stage (in the hall).

How many lumens would I need, bearing in mind there's going to be a lot of other light around (to light the actors)?

Do I need more lumens bearing in mind I'm projecting onto the wall and not onto a proper screen?

 

(I fleetingly wondered whether another alternative would be to install some kind of screen in about the position of the rear curtains (i.e. 1.2m from the back wall), and to rear-project onto it. However, this would be a very short throw, and I'm guessing it could be rather tricky installing some kind of temporary gauze/screen of around 4m x 3m)

 

Hiring isn't an option because we'd want to experiment with it for weeks, plus also use it for all subsequent productions.

Being a small orgnisation we don't have a lot of money spare, but we could maybe manage up to about £2K or £3K.

 

Regarding the content: I've seen other forum entries suggesting that running a VGA cable from the front of the hall (where the lighting control desk and laptop would be) to the rear (the stage) - total length 20 or 30 metres - would be better than HDMI.

Would VGA give a good enough quality image? i.e. would the resolution be high enough?

Are there any websites I could go to, to find backdrop content? E.g. maybe a park scene (static), or the view out of a train (moving)?

 

Is there anything else I need to consider that I've not thought of?

 

 

Any advice on this would be very much appreciated!

Thanks

[dbuckley]

I'll leave the projection to the experts, but, from what I've learned the hard way...

 

I will need to use it in conjunction with normal stage lights (fresnels and profile spots), mounted on a bar in front of the stage (in the hall).

Stage lighting falling directly on a projected image will wash that image right out. Or you get into an arms race with an image so bright that it puts the actors in silhouette, assuming you can afford projection that bright, so more stage lighting needed. Lighting angle needs to keep light off the image.

 

running a VGA cable from the front of the hall (where the lighting control desk and laptop would be) to the rear (the stage) - total length 20 or 30 metres - would be better than HDMI. Would VGA give a good enough quality image? i.e. would the resolution be high enough?

A decent VGA cable will certainly go that far. Whether the resolution will be adequate depends on a number of factors, primarily the size of the image and how far the audience are from the image. And, of course, the expectations of the creatives and the audience.

[the kid]

When I was looking at reasonable projection a few years ago It was £1000 per 1000 lumen give or take a bit.

 

When I did do some backdrop projection we found it worked far better on the "budget" scale to use as a scene setter rather than a cyc. A nice video of travelling worked really well.

 

And dont forget clamps and brackets to hang your projector that can add up, you could easily add £500 or so for brackets + cables + playback (laptop and or software etc)

[vinntec]

In our tiny theatre we do this fairly often using a decent presentation projector (ie. not a specialised extra bright stage one the RoH would have loads of). We normally project onto the cyc from a distance of about 4.5m from our LX1. This gives us a VGA 1024x768 image about 4m x 3m. We run our projector from the lighting desk using a Chamsys MahicHD media server and the douser is a DMX device one of our members made so also controlled by the desk. The projector is either on or off (and you can't just drop power to it to turn it off). The media server is mounted immediately above it and is controlled via ArtNet on a wireless LAN connection.

 

However as David pointed out, when we do this we have to shoe-horn the stage lighting considerably so as not to wash it out. This means there is no direct light on the cyc except the projector and the cyc lights dimmed when the projector is on. So all the stage lighting is cut to the bottom of the cyc, which means that instead of 2 rows of facelights, we might need 3 or 4 with the steepest causing skeleton faces upstage (as in "All or Nothing" below in my examples).

 

Next problem is that the projector will have a rectangular outline even when showing a "black" image - as it does not have a high enough contrast ratio (ours is 500:1). So we have made a DMX douser for it which physically blocks the beam. When it is on, you have a rectangular image and trying to disguise the edges of it is difficult for the same reason. If the lighting is stable (not building or fading) you can normally make the outline of the image close to the colour of the cyc lights at that moment and this works fairly well. Incidentally we have LED cyc lights and MagicHD allows us to play with the colours directly so we can do this fairly easily.

 

The beam from the projector is also very tall (almost as tall as our rig) and this causes problems with lighting physically downstage of it which either has to be over-bar mounted or kept out of the projectors beam. We have put special brackets in to lower the projector itself as much as we can but have to the image as high as possible so the actors don't stand in the beam!

 

Here are some examples from year before last: http://www.chesilthe...313985_orig.jpg where we have a blue space image with cyc lghts hiding the edge, this one http://www.chesilthe...096698_orig.jpg where the image was fine but actors are right in front of the cyc and lit with almost toplights, and http://www.chesilthe...735020_orig.jpg where the projection is a complete window so only need to put a little colour on the cyc.

 

So yes it is possible to do with fairly limited resources, but it is very very very very very complex and it has taken us years to get to where we are now without spending mega-bucks. Recent shows have included animations now that we know what to do (which was custom coloured so we could hide the edges). We are not always able to do what the director has in mind, as in the case for our next production as they wanted a street scene throughout but the lighting states changing many times (and with multiple builds and fades going on concurrently).

 

So if you have the projector you are going to use, arrange to go down to the venue and project it onto the wall from a table. See how big an image you can get versus how bright it is. Turn the lights off and look at the beam - imagine that upside down (which is how it on when on a lighting bar). Now look at whatever lighting bars you have a draw a mental line from the bar to the bottom of the wall (or at least the bottom of where you want the image to be). How far away from the wall do you have to be to still be lightable at a decent angle and at a steep angle. If your venue is basic, then you might not be able to light very much of the stage (at head height) at all without lighting the back wall.

 

Good luck!

[J Pearce]

Hanging a projector and pointing it at the cyc, and even keeping the stage LX wash off it is the easy bit. Content is the hard bit.

Rubbish content will look awful and draw away from the action. Have you any graphics designers/artists/photographers in your group who can help build good quality content?

[kerry davies]

See if you can borrow a decent presentation projector and play with it. Mine has a highish contrast and works better than some with higher lumens numbers.Though you can buy 10,000:1 contrast and 3000 lumens for £400 retail these days. Not seen one free with cornflakes yet!

 

Make sure the action is blocked with beams in mind and downstage a little, as vinntech suggests. Apart from that it is whatever suits you and the director but in a village hall throwing money at it may even be counterproductive. As Jon says, content will make or break the effect.GIGO.

[bagel]

Thanks for all your comments - they are most helpful.

 

@vinntec - Thanks for including pictures from your own productions. I hadn't thought about blending the edge of the image - whether that is possible at all in our space will depend on how even a spread we can achieve with our LEDs. I guess I was thinking that I would just attempt to get the image to fill as much of the space as possible (about 4m x 3m), which would save having to do that.

From your pictures I can see that you're projecting onto some kind of cloth. Is that any special material? Is it white? How do you manage to hang it with so few creases?

 

 

Does anyone have any opinions as to how to go about choosing a projector? There are so many, it's hard to know where to start. Is it essentially a case of a) deciding on the throw (as determined by where it's going to be mounted), b) the image size required (4mx3m), and then c) searching the web until I find one that looks like it will provide enough lumens to light a back wall (3000+?) ?

 

Thanks

[Shez]

This is a useful resource for identifying a projector to fit particular requirements.

[pmiller056]

Hi

 

I've used backdrop projection for amateur theatre. We have a FOH ceiling mounted conventional projector normally used for videos. The bottom of the projected image needs to be high enough not to illuminate the actors heads (and dazzle the actors) - moving the acting downstage can help a bit. As others have pointed out, any stray stage lighting will wash out the projected image. If you are careful with the blocking and masking of lighting, you can light the actors faces and not wash out the projected image. The fan noise from a FOH mounted projector can be irritating to the audience depending on the nature of the show.

 

For the next show we will try to use a short throw or ultra short throw projector ceiling mounted closer to the 'screen'. This will allow use of more of the stage space and move the fan noise away from the audience. A short throw projector needs a rigid and flat screen, so your wall should be OK (if the screen moves or billows at all with one of these projectors, it is glaringly obvious). Note that with a short throw projector, there is considerably less adjustment of zoom, focus and image geometry available than a normal projector so it needs to be mounted at the correct point in space for the desired image. Before you borrow/buy a short throw (or any) projector, download the instruction manual and look at the positioning and image size tables to see that everything can go together. There are plenty of used, working projectors available on ebay, so you could buy one for your show and sell it on afterwards for minimal overall cost. Remember for a given lumen output from the projector, a smaller image will be brighter than a large image.

 

VGA over 30m is do-able, although such a lead can be expensive to buy. If you can get Cat-5 network cable at minimal cost, then consider using some VGA over Cat-5 adapters which should allow operation up to 100m or so at a similar cost. HDMI or DVI beyond a few meters can be awkward or expensive depending if all the equipment chooses to play nicely together!

 

Regards

 

Peter

[vinntec]

@vinntec - Thanks for including pictures from your own productions. I hadn't thought about blending the edge of the image - whether that is possible at all in our space will depend on how even a spread we can achieve with our LEDs. I guess I was thinking that I would just attempt to get the image to fill as much of the space as possible (about 4m x 3m), which would save having to do that.

From your pictures I can see that you're projecting onto some kind of cloth. Is that any special material? Is it white? How do you manage to hang it with so few creases?

The cloth is our cyc which is about 2 years old. It is even less creased now as we have rehung the bar it was on and put stretchers either side. It is a 5.5m wide x 5.4m high white cyclorama cloth from J C Joel. Behind it is a dark blue wall with a big blacked out window and radiators so we can't paint the back wall. If I remember correctly it is a seamless poly-muslin material.

 

The blending of the projected image is more of an issue when the production is realistic rather than abstract. So a row of houses which starts and ends in mid-air and has the lower portion missing takes some explaining to the minds of the audience - but abstractly a few windows works perfectly well especially if the "house" is the complete image. However you can disguise the edges many ways other than lighting - you could use foliage, a groundrow scene along the bottom (usually away from the cyc/wall), borders etc etc.

[stevep]

Given that you could be potentially prepared to commit up to £3k on this - it'd be worth pricing up the hire instead, you may be surprised how cheap it can be.

After a couple of hires you'd have then built up enough knowledge of the specifics in your venue to make a more informed purchase decision. (and the company you've been hiring off may do you a good deal on a purchase)

 

where are you based?

[alistermorton]

Just to add my two penn'orth - we used ordinary "business" projectors with fairly short throw lenses for many years, with a home made DMX douser fitted for when you don't want the projector illuminating proceedings.

 

Mounted up just inside the pros just ahead of bar #1, the throw is about 5m. The projector has a setting for ceiling mount for adjusting the orientation and keystoning. Projecting onto our white cyc hasn't been a problem as long as the stage lighting is arranged to avoid directly hitting the cyc (as Vinntec alludes). We can usually get away with the action being 1/2 to 2/3 of the way upstage before shadows become a problem. If we need to go further upstage we've done things like only projecting onto the top half of the cyc and filling the gap with set.

[bagel]

Given that you could be potentially prepared to commit up to £3k on this - it'd be worth pricing up the hire instead, you may be surprised how cheap it can be.

After a couple of hires you'd have then built up enough knowledge of the specifics in your venue to make a more informed purchase decision. (and the company you've been hiring off may do you a good deal on a purchase)

 

where are you based?

 

Maybe that's not such a bad idea. We're in East Yorkshire.

 

 

Just to add my two penn'orth - we used ordinary "business" projectors with fairly short throw lenses for many years, with a home made DMX douser fitted for when you don't want the projector illuminating proceedings.

 

Mounted up just inside the pros just ahead of bar #1, the throw is about 5m. The projector has a setting for ceiling mount for adjusting the orientation and keystoning. Projecting onto our white cyc hasn't been a problem as long as the stage lighting is arranged to avoid directly hitting the cyc (as Vinntec alludes). We can usually get away with the action being 1/2 to 2/3 of the way upstage before shadows become a problem. If we need to go further upstage we've done things like only projecting onto the top half of the cyc and filling the gap with set.

 

That's encouraging to hear that you've successfully used "ordinary" projectors - and interesting that you managed to get it to work from just behind the proscenium with a throw of 5m - which is the same distance as applies to ours (although our stage ceiling is rather low, I think, at 3.2m) . It's starting to sound more doable...

[timsabre]

We're not that well provided for with AV suppliers in East Yorks...

Tega office in Hull might have a few models in stock you could try out, or there is Saville.

 

Now I know the venue we are talking about (came for an LED shootout with you last year), you do have quite a low headroom on the stage. A short throw projector might work out better to avoid hitting actors, but they are more expensive and less adjustable than "normal" ones.

[alistermorton]

(although our stage ceiling is rather low, I think, at 3.2m) . It's starting to sound more doable...

 

Off the top of my head I think our height for the projector is about 4m.