lighting washing out my projector

[bcastle]

Like most churches on a limited/non existent budgets I have to be creative when coming up with solutions to problems. One of our predominant problems is that our underpowered, 2000 lumen 5 yr old projector gets washed out because we have 8-600 watt stage lights, 4 on each side of the projector. (the par cans are close to, if not actually are the american dj par-64 variety). Our projector is probably 25-30 feet from the screen and the lights are positioned such that two lights are focused at one spot, ie 2 lights per fader on my dmx controller. I would like to make it 8 separate positions on the stage but that's another time.

the projector is mounted on a box that can be raised and lowered via wench in the attic. the box is 4'x2' (same size as ceiling tiles). the lights are mounted on a galvanized steel pipe that literally passes through the box. ( i can see it in the attic.

My main question is that I want to first move the lights. there is a truss in the attic about 4 feet behind where the lights current reside and it runs widthwise across the building. in theory i could cut the pipe in half, move the light assemblies (4 per side) back and to the side (left and right). I imagine this will help out with some of the washing out.

Our minister of music has been wanting to do this anyways and our pastor is receptive to the idea. We eventually will go to a truss and buy a newer projector, just dont have the funds just bought a new mixer a month ago.

I have experience in rigging from my life of offshore commercial diving, so putting 50-100lbs in the air isnt really a problem for me seeing as i've put up several 100 tons in the air before. What is the best way to go about mounting my pipe to the truss? Best I can come up with is eye-bolts in 3 spots ( so if one end goes i dont make a pendulum) completely through the pipe, then connect this to a cable rated for way more than what i need (ie each cable should be able to support the entire load, plus some, by itself. Finally the other end to another eye-bolt that is drilled through truss and double nutted.

Any thoughts?

[cmchamp]

Premier, OmniMount and others make a truss mount adaptor for projector mount pipe. Off the top of my head, can't tell you the models of those two manufacturers, but I'll try to get it to you sometime this weekend.

[bggowing]

Cory,

Are you referring to this?
http://www.markertek.com/Audio-Equip...PA-BLACK.xhtml

[bcastle]

i think something like this:
http://www.markertek.com/Lighting-Ba...er/C4463.xhtml

[snlgraham]

What type of truss are you talking about? Is this stage truss? Or clear span ceiling truss? I-beam?
In my church we have steel I-beams running through the ceiling. I just used beam clamps to attach channel strut to the beams and then from the strut ran threaded rod down through the ceiling. Threaded rod is stiffer than cable. You can get all this at home depot.

[bcastle]

this is a ceiling span truss that spans the entire width of the church and is somehow connected to a truss that runs length wise down the sanctuary. Cant really see the connection because we have a deck that runs the sanctuary front to back. makes it easy for cable runs. but for the most part is all bolted connections using, 1/4" or 3/8" double angle brackets

the bottom members of the truss are more like two angle brackets touching back to back with the flats facing downward and then they do the same thing going diagonally to another attachment point. I also thought of all-thread but mainly because i can adjust it more precisely than a cable.

[snlgraham]

Something like this? The first is for threaded rod and the second is for channel strut.
What I like to do is attach channel strut to the ceiling structure and then attach threaded rod to the strut. This way you can move the hang point along the strut and get it exactly where you want it. Works really well for aiming speakers. Also good to manouver around T-bar ceilings.
Home Depot in the electrical section.

[bcastle]

Thanks for the ideas guys. I will def keep this in mind for our projects in the future.

[ptechie]

From your post I understand that you are using 8 - 600 watt PAR 64 lights as front lights. The resulting effect you are trying to correct is the washing out of your screen.

I think the easiest is to reduce the amount of non-projector light hit the screen. PARs can be hard to control. However, there are many things you can do.

Move the lights closer to the stage - this will increase the downward angle and more light will be aimed at the stage floor and not the back wall. (assuming you don't have a polished floor to reflect the light)
The downside to this is you will see more shadows on the face the closer to directly overhead you get.

Move the lights further to the sides. If you angles are steeper your lights will spill off stage and not directly back into your screen. If you have one from either side then you can cancel out the shadows.

Replace your lamps with those of a tighter beamwidth. The size of the area a PAR makes is dependent on the lamp you use. If you replace the lamps with a medium or narrow your spots on the stage will be smaller and brighter and the spill will be less. Here is an article about this.
onstagelighting.co.uk/lighting-equipment/par-64-bulbs-a-guide-to-par-64-lamp-sizes/

Finally you can use a barn door or black wrap (essentially black aluminum foil) to shutter the light off the screen.

Good luck and let me know if you need any clarification.

[bcastle]

I took a different approach to the situation and looked up the ideal mounting distance from the screen the projector should be. it was 8 ft too far. spoke to my pastor and he said the only reason they put it there was because the other church had their projector there. wrong answer. i moved it forward. it helped a little, but not much. it basically comes down to the fact that our projector is the wrong application. ie it only has 2000 lumens. it looks fine with all the lights off, but that's not how we use it. were in the process of saving up some money to get the viewsonic pro 8500, 5000 lumens of awesomeness.