Rear Screen Projection dilema

[chercarlop]

Has anyone in the history of projection ever used 2 projectors on the same rear screen to add brightness without adding more brightness to the hotspot?

Our consultants say there is no solution to our situation. In our sanctuary we have a 9 by 12 screen with a 1.8 gain made by dalite. Our projector is an Eiki 4100 ansi lumen with a short throw lens, centered to the screen. It is hung from a centered beam 10 feet back from the screen. It cannot go back any further because the beam angles down.

The problem is the projector is not bright enough, period. We are experiencing a minor hot spot (light from the projector lens) in the center of the screen. We are told we cannot go brighter without having a huge hotspot problem.

My question to anyone who knows projectors is can we add another projector (say 2000 lumens) to the same screen, place it on the floor, and keystone it to fit the screen? Would this be possible? Would it add brightness to the overall screen without adding too much to the hotspot. I NEED to brighten the overall screen projection. I must find a way.

Understand this is becoming a real issue with me and I becoming really frustrated with the entire media set up that we have. I am doing all I can to find a solution to this problem.

SOS

[Gene]

Not sure on the second projector.

But if you can't brighten the projector, can you reduce the ambient light hitting the screen?

Got a picture of the setup? Maybe one of the creative minds here can figure out a solution.

Originally Posted by Gene

Not sure on the second projector.

But if you can't brighten the projector, can you reduce the ambient light hitting the screen?

Got a picture of the setup? Maybe one of the creative minds here can figure out a solution.

When i was on tour with MWS we had 9 barco light cannons, 3 screens, 3 cannons per screen

each was set up, one cannon was red, the 2nd in the stack was green, the last in the stack was blue, no hotspots, but a pain to set up and align

thats the only way i can figure out how to avoid it, i am sure one the the better seasoned projector guru's will know more

[chercarlop]

The lighting set-up is always changing. I am constantly having to tell the guys operating the lights to dim them down but they tend to just go with the presets that the worship pastor cues up the way he wants the stage to look. Because of the way the lights are situated, there is always some light on the screen. It is the way it is set up. Some are above the screen shining down. Some show the shadows of the spinning ceiling fan and sound speakers on the screen area. Some shine down at an angle. Some are flood lights

No matter how many times I tell them, there will always be too much light on the screen. I get tired of being a nag. I wish they could see the point that it starts to wash out. But they don't see it or ignore it so I need a brighter projection.

So maybe you can have two projectors pointing at the same screen... I want to try it next week unless someone else knows why it may not work.

[Gene]

Let us know how it works...someone else will doubtless face this same issue in the future

It sounds like the lighting folks need a smack upside the head ^H^H^H^H^H er... I mean, to deal with the lighting problem on a more permanent basis. Are they regular fixtures, or theater-style spots and floods? If the latter, they can put barn doors on some fixtures to control light spillage. If the former...well, I know your pain...that's what we've got at the moment

[chercarlop]

It's mostly the spots and floods. Well, mostly the floods. The normal fixtures are not a problem.

[Gracetech]

Hi i remember your previous post and you are far from out of options. First i would like to say you need to have a Pow-Wow with the pastors and techs and get everyone on the same page. Until you know that everyone knows the issue and everyone knows that everyone knows the issues you will continue to have issues. Some times people don't set their priorities high enough until they know other people know about the issues. That said make sure they clean up the lights. If they say they can't then obviously they have no clue what their doing or just don't care. In that case drop the price of a Christie DS+8k in their laps that tends to get results. If you are looking to solve your problem from a crank up the projection scenario you can go about it a couple of ways. You can stack some projectors and have to fight the color match and keystone and resolution and........ Or you can get a brighter projector like the fore mentioned Christie something in the 8k lumen range. Your installer is incorect in telling you that you cannot move your projector. You can use first surface mirrors(aka cold mirrors) to bounce your image. FS mirrors are used in projection screen tvs and such. I use them alot for compact installation of rear projection in churches. Now the mirrors are more expensive than just standard mirrors but sometimes it is just needed. I hope that your problems don't bog down your ministry cause i hate to see people get upset at things and get consumed with it. I'll be praying for you and your church leaders and tech team to pull eveything toghter.

crt

[Carl Godsoe]

The conference room where I work has a rear projection screen. The projector sits just below the screen and is aimed at a mirror apparatus that extends back from the screen about 5-6 ft. I know that there is more than one mirror, maybe as many as three to accomplish this. It was set up by one of the local projection companies. I'll have to look at it again on Monday. It's a real interesting set-up.

Originally Posted by chercarlop

So maybe you can have two projectors pointing at the same screen... I want to try it next week unless someone else knows why it may not work.

i am not well versed in projectors, but from my experience in other facets of media drives this answer

i recall in my college days that 98.5 degrees plus 97.0 degrees does not = 195.5 it equals 97.75 Degrees it is the SUM of the temp not the total of both

i suspect 2000 lumens + 2000 lumens will not equal 4000 lumens, it will equal both divided by 2

why it may not work, you can have identical projectors made one right after the other, and they will both be different somehow, color, contrast, even the bulb, the color panel might be off just enough etc

in my MWS tour, 6000 lumens X 3 will = 18,000 lumens, because each projector on the stack produces only 1 color from different light sources not 3 colors from the same light source

[chercarlop]

Originally Posted by Gracetech

Or you can get a brighter projector like the fore mentioned Christie something in the 8k lumen range. Your installer is incorect in telling you that you cannot move your projector.

No we are told by both our video consultant and Dalite screen company that we cannot go brighter with a single projector. We are on the borderline of extreme hotspotting. Right now when you put up a white background you see the lens. But dark backgrounds and digital pics just go black.

That's why I wondered if a second projector would solve the problem and add some brightness to the entire surface of the screen. We have a 4100 and if we add a 2000 lumen that would be 6100, maybe it could be even brighter than that. I don't know. If we got the same brand of projector it would seem like the color would be pretty close.

I am looking for someone who has actually done this.

Originally Posted by Gracetech

You can use first surface mirrors(aka cold mirrors) to bounce your image. FS mirrors are used in projection screen tvs and such.

Dalite said that mirrors would not solve the problem in our case. We use a short throw lens 10 feet back.

[Gracetech]

Dalite said that mirrors would not solve the problem in our case. We use a short throw lens 10 feet back.

I was just saying that projector position wise you had options in moving it around by using a FS mirror to get the correct trajectory. It seems to me as it seemed in your other post that your screen is holding you back. But i would highly recomend the "talk" with everyone involved to improve lighting issues. I would also recommend getting a different screen. You might have to go with a lower gain but you will not have the hotspotting that your currently have.

crt

[chercarlop]

Originally Posted by Gracetech

I would also recommend getting a different screen. You might have to go with a lower gain but you will not have the hotspotting that your currently have.

I've been in circles with the screen. If we purchased one with no gain and got a brighter projector it would come out the same. I need a significantly brighter projection.

One side claims we cannot go brighter with the projector without "extreme" hotspotting, the other side claims he can get rid of the hotspot and get a much brighter image but he charges$1000 expenses to come here and "prove" it and my supervisor says that's too much money for something that may not significantly improve the problem.

I just need to find a way. Has anyone ever used a projector stacker?