# Youth Room Stage Design



## Vitaliy (Sep 21, 2012)

Hi everybody.

Recently, we've been thinking of a stage design for our youth room that is to be remodeled. We really like the concept of a grid of squares and went off that to design a stage. I've attached a picture of the design.

My question is, what material should we use for the squares? They're 18x18", and we want them to be semi-transparent, so we can put lights behind them. The lights that we have chosen are PAR36 cans that are RGB color mixing LED's.

Any thoughts welcome!


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## gafftaper (Sep 21, 2012)

Off the top of my head you have three choices:

-Plastic (in the Seattle area we have a company called Tap Plastic who can get you anything, check for something similar in your area)

-Coroplast, not as rigid as plastic but reasonably priced. The "clear" coroplast is semi opaque but great for projecting color on it. Maybe put some clear plexi-in front of it to protect it. 

-Tricot, stretchy fabric which takes colors really well from backlight.


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## museav (Sep 21, 2012)

Okay, I'll ask the stupid question but are you addressing the stage floor, stage ceiling or upstage wall? And what is the "202" Diagonal (32:10.35 Aspect Ratio)" rectangle?

LEDs should certainly help with lamp life and heat, but some access and ventilation may still be necessary.

I'm showing my age but I have to admit that the first thing that came to my mind was Saturday Night Fever (John Travolta) - You should be dancing - YouTube.


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## Vitaliy (Sep 23, 2012)

gafftaper said:


> Off the top of my head you have three choices:
> 
> -Plastic (in the Seattle area we have a company called Tap Plastic who can get you anything, check for something similar in your area)
> 
> ...



Thanks for your reply. I'm actually located in Seattle as well!

I'm confused though, because of all the options that every plastic company has to offer. I've never done anything like this before, so don't know what's best for us.
What type, thickness, etc. would you recommend?

We're trying to achieve an effect similar to this, but with backside illumination.


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## Vitaliy (Sep 23, 2012)

museav said:


> Okay, I'll ask the stupid question but are you addressing the stage floor, stage ceiling or upstage wall? And what is the "202" Diagonal (32:10.35 Aspect Ratio)" rectangle?



This is for the stage background, so I'm guessing upstage wall. I'm new to these terms

The "202 Diagonal (32:10.35 Aspect Ratio)" rectangle is our proposed projector screen. It's going to be made up of two ultra-short throw projectors that are put next to each other, creating a super-widescreen image. 

I did this mostly because our management was about to buy an 80" TV for $2500. I stopped them at the last second. This screen will cost us $2000, everything included. I think this beats the 80" TV that they wanted to buy!


museav said:


> LEDs should certainly help with lamp life and heat, but some access and ventilation may still be necessary.



Yeah, that's why we chose the PAR36 cans in this situation. They're $50 each, which isn't much for a LED can but is a lot when you add them up to make an "app wall" stage. I wish we can use LED strips to light up these squares, but I can't find (or looking in the wrong place) ones that can be divided into 18" strips and controlled individually through DMX.


museav said:


> I'm showing my age but I have to admit that the first thing that came to my mind was Saturday Night Fever (John Travolta) - You should be dancing - YouTube.



Haha not quite what we want, but I see why you thought of that!


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## ruinexplorer (Sep 23, 2012)

When you figured the savings on the TV over the two projectors, did you consider lamp life? Also, how are you planning on blending the two images? Ultra short throw lenses are intended to be used by themselves. Since the image flares at the edges due to the nature of the lens, you will not get the normal square lines you might be used to with a standard lens.


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## Vitaliy (Sep 23, 2012)

ruinexplorer said:


> When you figured the savings on the TV over the two projectors, did you consider lamp life? Also, how are you planning on blending the two images? Ultra short throw lenses are intended to be used by themselves. Since the image flares at the edges due to the nature of the lens, you will not get the normal square lines you might be used to with a standard lens.



Yes, I did. The projector has a 3000 hour lamp life when operating at its normal mode. When switching to eco-mode (which we will do, because 3100 lumens is too bright due to no ambient light at all) the projector has a 4000 hour lamp life. Lamps are $250 each, which is not a problem if each lamp will last us 3-4 years.

I did not know this. We actually changed our projector choice because of some factors, from an "ultra-short throw" to a "short throw". Will we still experience these image flares? What exactly happens with these lenses?

Thanks for warning me about this...

The projector that we want is the Optoma TW610ST.


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## emac (Sep 23, 2012)

I think what ruinexplorer touched upon is a crucial factor. Going the edge blending route complicates things very quickly. Especially with short throw projectors. 

I would think that having a tv, even if it is a larger Capitol expense, would be easier in the long run for a youth room. Having one thing that needs be controlled, the tv, would be simpler and more future proof then having two independent image sources. And on top of having the two projectors, you would need a computer with at LEAST two display cards, (most likely a third for a control monitor) which would mean a fairly powerful computer with specialized software, which all together would most likely cost more then your $500 saved by going with the projector plan. 

If you went with the tv, you would just need a computer with two independent display outputs and you would have a great control system with out specialized software. You might even have a computer in your facility that could handle something like this. 

Also, I am not sure on what your relationship to this facility is, but if you are a volunteer, going the tv route will help with the training of other staff/volunteers and help with somebody using the system once you no longer at the facility. 

Be prepared to also account for potential cabling costs, construction of the frame work costs, software costs and training time and commitment. 

Building something so large that is a permanent structure might also require permitting. This might be something you would want to contact a local theatre professional, Seattle Scenic Studios (a Seattle based scene shop), or PNTA (a theatre retailer to see whether they could build it for you. 

If you do build it your self then poly cyc (which PNTA sells) stretched over a frame might also be an option for the opaque sections.


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## Vitaliy (Sep 23, 2012)

emac said:


> I think what ruinexplorer touched upon is a crucial factor. Going the edge blending route complicates things very quickly. Especially with short throw projectors.



Can we use a standard throw lens projector? I'd have to check first if that'll work in our application, but if it were to work would I achieve this screen?

We're not trying to save money on a screen (although our budget is limited), instead I was trying to get a larger screen than the 80" that they were thinking about buying. Is there anything we can do (within a reasonable budget)?


emac said:


> I would think that having a tv, even if it is a larger Capitol expense, would be easier in the long run for a youth room. Having one thing that needs be controlled, the tv, would be simpler and more future proof then having two independent image sources. And on top of having the two projectors, you would need a computer with at LEAST two display cards, (most likely a third for a control monitor) which would mean a fairly powerful computer with specialized software, which all together would most likely cost more then your $500 saved by going with the projector plan.
> 
> If you went with the tv, you would just need a computer with two independent display outputs and you would have a great control system with out specialized software. You might even have a computer in your facility that could handle something like this.
> 
> Also, I am not sure on what your relationship to this facility is, but if you are a volunteer, going the tv route will help with the training of other staff/volunteers and help with somebody using the system once you no longer at the facility.



I was planning to use a Matrox DualHead2Go screen splitter. That way we can output 2560x800 from the computer, and the Matrox will split it for two projectors. This route ensures that we won't need to buy any special equipment in order to run this screen. Training, too, won't be any different from a standard screen with this setup.

If any of you had experience with the DualHead2Go, please let me know. I've only seen it in action in other churches, but never used one myself.


emac said:


> Be prepared to also account for potential cabling costs, construction of the frame work costs, software costs and training time and commitment.
> 
> Building something so large that is a permanent structure might also require permitting. This might be something you would want to contact a local theatre professional, Seattle Scenic Studios (a Seattle based scene shop), or PNTA (a theatre retailer to see whether they could build it for you.
> 
> If you do build it your self then poly cyc (which PNTA sells) stretched over a frame might also be an option for the opaque sections.



Actually, the $2000 included the two projectors, all the cables needed, the Matrox, and the projector mounts. We were planning to build this ourselves, and do have people who can help us out with this. As with software, we have that covered too, since the computer isn't doing anything "special" thanks to the Matrox.

As for the poly cyc, would we be able to achieve the rounded edges of the squares with this material, as shown in the design? Also, if we were to get this would we be able to backlight it and change colors (if we were to get grey, for example)?


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## museav (Sep 23, 2012)

This has been a topic in many trade magazines and in some recent conversations but flat panel display are often replacing projection for 100" and under diagonal images, which is about the size of each of your projected images. And some commercial flat panels you may not even require any external processing for the dual image desired as some models incorporate integrated tiling capability. 

A 202" diagonal, 32:10.35 format image is approximately 62.2" high and 192.2" wide. Your projectors are native 1280x800 or 16:10 format so they would each produce as 62.2" high by 99.52" wide image and two of those side-by-side would be 62.2"x199.04". So you seem to have some overlap, in this case 6.84" or just under 7%, which does suggest edge blending. How are do you plan to perform the edge blending?

For a 62.2" high image the Optoma TW610ST requires a 4'-4" throw. There is no zoom capability so you will have an exact throw required with no variation in order to get the images to fill the screen. For that image size the projector apparently also wants to be located approximately 1' above the screen for ceiling mount or 1' below the screen for desktop mount. The TW610ST does have keystone correction but you do not want to be dealing with keystoning if you are adge blending. So the projectors apparently need to be at very specific locations both vertically and horizontally. Realistically, if you are planning on edge blending getting short throw projectors with no image shift or zoom capability projectors to align properly in the overlap area could be very challenging.


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## jxgriffi (Sep 23, 2012)

Vitaliy said:


> Thanks for your reply. I'm actually located in Seattle as well!
> 
> I'm confused though, because of all the options that every plastic company has to offer. I've never done anything like this before, so don't know what's best for us.
> What type, thickness, etc. would you recommend?
> ...



Just so you know, those in the image you provided are being up lit, not backlit. There are Mega-lite NE Color wash units on the floor uplighting them. (yes, I know the TD at Southhills)


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## ruinexplorer (Sep 23, 2012)

Vitaliy said:


> Can we use a standard throw lens projector? I'd have to check first if that'll work in our application, but if it were to work would I achieve this screen?


If you were to use a standard lens, you would likely need to fold the image using top surface mirrors to save on distance. Essentially making the screen similar to a projection TV. Here's an article where you can learn more about this. However, this will add yet another level of complexity and cost to this set-up.



> I was planning to use a Matrox DualHead2Go screen splitter. That way we can output 2560x800 from the computer, and the Matrox will split it for two projectors. This route ensures that we won't need to buy any special equipment in order to run this screen. Training, too, won't be any different from a standard screen with this setup.
> 
> If any of you had experience with the DualHead2Go, please let me know. I've only seen it in action in other churches, but never used one myself.



The Matrox will only allow you to generate a larger resolution than either one of the projectors would produce natively, thus allowing you to have the image partially displayed by each unit. Unfortunately, this was intended for monitors, which does not require the images to perfectly align. What you are hoping to do is to perfectly align the image along the edge, you cannot do this with the ultra short throw lens. As Brad suggests, having an overlap of your image will provide a better extended image, but you will need additional processing for this to happen. This is not just a set-up that the janitor can turn on before the room is used. It will take a trained technician. Your best bet is for a single display (either one projector or monitor). Also, don't forget to factor in maintenance which is considerably different for monitors and projectors (see my article here).


> Actually, the $2000 included the two projectors, all the cables needed, the Matrox, and the projector mounts. We were planning to build this ourselves, and do have people who can help us out with this. As with software, we have that covered too, since the computer isn't doing anything "special" thanks to the Matrox.
> 
> As for the poly cyc, would we be able to achieve the rounded edges of the squares with this material, as shown in the design? Also, if we were to get this would we be able to backlight it and change colors (if we were to get grey, for example)?



Are you trying to get individual squares to have their own colors or have light shine through only where the squares are so that the entire thing is backlit with fewer fixtures? But if the material is grey, it will have some effect on the color, but you will still be able to have a range of colors.


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## MNicolai (Sep 23, 2012)

I can't help but think you're copying someone else's architectural and/or scenic and/or lighting design almost verbatim. If I spent a lot of time designing that room, I would not be very pleased if someone copied my design without first seeking my permission. I'm not certain in this situation that there would be any potential legal ramifications for copying it, but be mindful that you are effectively stealing someone else's intellectual property.


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## Vitaliy (Sep 23, 2012)

museav said:


> This has been a topic in many trade magazines and in some recent conversations but flat panel display are often replacing projection for 100" and under diagonal images, which is about the size of each of your projected images. And some commercial flat panels you may not even require any external processing for the dual image desired as some models incorporate integrated tiling capability.



Yeah I know, but 100" flat panels are definitely not in our budget. 


museav said:


> A 202" diagonal, 32:10.35 format image is approximately 62.2" high and 192.2" wide. Your projectors are native 1280x800 or 16:10 format so they would each produce as 62.2" high by 99.52" wide image and two of those side-by-side would be 62.2"x199.04". So you seem to have some overlap, in this case 6.84" or just under 7%, which does suggest edge blending. How are do you plan to perform the edge blending?



Yes, I know. I was planning to mount the projectors so the edges are next to each other, and then blocking off the excess 3.5" or so on each side using black felt. Do you think this is the right thing to do? We can't do any edge blending, because we do not have the budget for the equipment that can do it.


museav said:


> For a 62.2" high image the Optoma TW610ST requires a 4'-4" throw. There is no zoom capability so you will have an exact throw required with no variation in order to get the images to fill the screen. For that image size the projector apparently also wants to be located approximately 1' above the screen for ceiling mount or 1' below the screen for desktop mount. The TW610ST does have keystone correction but you do not want to be dealing with keystoning if you are adge blending. So the projectors apparently need to be at very specific locations both vertically and horizontally. Realistically, if you are planning on edge blending getting short throw projectors with no image shift or zoom capability projectors to align properly in the overlap area could be very challenging.



Yes, as for specifications and measurements, these projectors will be perfect for this screen. However, as ruinexplorer pointed out, the short throw lens in the projector might not work in this situation.


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## Vitaliy (Sep 23, 2012)

jxgriffi said:


> Just so you know, those in the image you provided are being up lit, not backlit. There are Mega-lite NE Color wash units on the floor uplighting them. (yes, I know the TD at Southhills)



Yeah, we just liked the appearance of the "app wall" type of design. The reason why we chose to have them backlit was so we can individually control each square, thus allowing us to change the pattern, color, etc..


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## Vitaliy (Sep 23, 2012)

ruinexplorer said:


> If you were to use a standard lens, you would likely need to fold the image using top surface mirrors to save on distance. Essentially making the screen similar to a projection TV. Here's an article where you can learn more about this. However, this will add yet another level of complexity and cost to this set-up.



So you recommend a standard lens for this application? Is there any way to achieve the screen mentioned above with this particular projector and lens, or is it simply not possible?


ruinexplorer said:


> The Matrox will only allow you to generate a larger resolution than either one of the projectors would produce natively, thus allowing you to have the image partially displayed by each unit. Unfortunately, this was intended for monitors, which does not require the images to perfectly align. What you are hoping to do is to perfectly align the image along the edge, you cannot do this with the ultra short throw lens. As Brad suggests, having an overlap of your image will provide a better extended image, but you will need additional processing for this to happen. This is not just a set-up that the janitor can turn on before the room is used. It will take a trained technician. Your best bet is for a single display (either one projector or monitor). Also, don't forget to factor in maintenance which is considerably different for monitors and projectors (see my article here).



Sadly there is no way we can dig up the money for video processors that will enable us to overlap the image and blend them. About the setup and maintenance, we have that covered, as we've been maintaining projectors in our main sanctuary well over 6 years.

With the Matrox I was actually hoping to simplify the setup. If we were to do edge blending, then yes, it would be too complicated for the volunteer to use.


ruinexplorer said:


> Are you trying to get individual squares to have their own colors or have light shine through only where the squares are so that the entire thing is backlit with fewer fixtures? But if the material is grey, it will have some effect on the color, but you will still be able to have a range of colors.



That's what our goal is - so we can individually control the brightness and color of each square. If not, we might just opt for having it backlit, with fewer fixtures.


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## Vitaliy (Sep 23, 2012)

MNicolai said:


> I can't help but think you're copying someone else's architectural and/or scenic and/or lighting design almost verbatim. If I spent a lot of time designing that room, I would not be very pleased if someone copied my design without first seeking my permission. I'm not certain in this situation that there would be any potential legal ramifications for copying it, but be mindful that you are effectively stealing someone else's intellectual property.



I'd like to point out two things. 

First, this design was found at churchstagedesignideas.com -- a website dedicated to churches trying to find some inspiration when designing their stages. That's exactly what we did here. We took an idea that we liked, and made our own version of it. In fact, when looking through the site, I found a number of designs similar (app wall) to the one that we chose as our favorite. I don't think that we did anything wrong when we used a grid of squares in front of a black background in our design. I think our design is quite different from the idea that you claim we have "copied". Sure, it does look similar. But I've noticed that cars are similar as well because they have four wheels and a transmission. If you researched on what you were about to say, you would have found that the designer of the stage, "Van Metschke at South Hills Church in Corona, California loosely based this design on a stage he saw at Mariners church in Irvine, CA.". So is he now copying the Mariners church? You can see it for yourself here.

Second, I'd like to state that the ideas were designed by a church, for a church. Nobody was trying to earn money off their design. Our design is also for a church (although I can't imagine how our design seemed so similar to the original for you to state that we were "copying"). In fact, I was on the same website a couple of days ago, and I attached the image of our design for them to see. Was I pronounced as "copying" someone else's design? No. I was asked to post pictures of the finished product. Who knows? Maybe my design will serve as inspiration for another church seeking to make their place more attractive!

So, in conclusion, I will tell you that we never copied anyone. Did that stage serve as inspiration for our design, and does looking at it remind one of other stages with squares and rounded corners? Sure! But I think it's wrong to pronounce someone as "copying" someone else just because certain aspects are similar.


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## MNicolai (Sep 23, 2012)

If you have the designer's blessing because they've explicitly granted it to others for their use, then you're right in that it's not stealing. It _is_ still copying. Don't think you've got an original design there, you don't. That does not seem to matter to you though.

As for the designer taking it from another church, I'd say the same thing to him, except the keyword in his case is that he "loosely" based it on another venue.

If this is the correct venue Van Metschke was referring to at Mariners, I would say he did have an original design because there are huge differences between this design and his:





There are _not_ huge differences between your design and his. Yours has almost the exact same elements, rearranged only a little differently than his. Back light, front light, whatever -- it's pretty much a carbon copy.


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## ruinexplorer (Sep 23, 2012)

Please, let's not turn this into a battle about intellectual property. Let's leave that to Apple and Samsung.

Now, if it were my design, under the constraints of the two projectors to get a larger image, I would personally have a hard seam between the two halves of the image (essentially simulating two monitors, even if the fabric is seamless). This way, I could stick with the two ultra short throw projectors. The perception will remain as a continuous image as people will end up ignoring the seam. However, this would give you flexibility to have two separate images side by side without it looking "off". While adding in the mirrors and standard lens could get you the semblance of a seamless image, the complexity and aggravation would not make it worth the time. Every minor tweak could ruin the illusion of the seamless image while having the seam will allow you much more flexibility.

You should see if you can get two projectors as a demo and see how the image looks.


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## museav (Sep 23, 2012)

Vitaliy said:


> Yes, I know. I was planning to mount the projectors so the edges are next to each other, and then blocking off the excess 3.5" or so on each side using black felt. Do you think this is the right thing to do? We can't do any edge blending, because we do not have the budget for the equipment that can do it.


The projectors do not create that clean an edge, one reason why you see front projection screens with non-reflective borders. You can probably make what you are considering work well enough to get an image, but you're likely to have some noticeable issues at the center and really wonder if it might not be acceptable and much simpler with a single image.

I'm not sure that you understand the issues regarding setup and maintenance. To have a clean transition where the two images meet you are talking about getting 800 0.078" high pixels from each projector to line up with one another other with their edges exactly meeting and doing so with projectors with a fixed short throw lens, no lens shift and limited geometry correction. If you can get that to work then you are also looking at changes that occur over time, movement in the mounts, etc. meaning having to readjust the projectors. In general, you are almost certainly looking at much greater setup and ongoing maintenance than if it were simply two projectors independent of one another.


As far as the 'copying' issues, obviously, people take inspiration from many things, but there can be a fine line between taking inspiration from something and copying it and just where that line falls can be up to the parties involved and the courts. However, it being created by or for and physically in or part of a church is likely irrelevant to the issue.


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## cpf (Sep 23, 2012)

Another option for the dual-projector scenario is giving up on having a semblance of 1 continuous image and just putting a thin-ish strip of masking down the center that's just enough to hide the spill. When running content across both "screens" people might notice it at first, but if the show is so boring that people are left to contemplate the setup of your projection, you have bigger issues.


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## Vitaliy (Sep 24, 2012)

ruinexplorer said:


> Now, if it were my design, under the constraints of the two projectors to get a larger image, I would personally have a hard seam between the two halves of the image (essentially simulating two monitors, even if the fabric is seamless). This way, I could stick with the two ultra short throw projectors. The perception will remain as a continuous image as people will end up ignoring the seam. However, this would give you flexibility to have two separate images side by side without it looking "off". While adding in the mirrors and standard lens could get you the semblance of a seamless image, the complexity and aggravation would not make it worth the time. Every minor tweak could ruin the illusion of the seamless image while having the seam will allow you much more flexibility.



That's a great idea. I'll draw that out, and present it to the team. If the projectors turn out to create a perfect seamless image (which they probably won't) we are lucky and won't have to create the seam. That way we'll be able to have a Plan "B" if positioning the projectors will prove too difficult or like you said, the short throw lens will not make an even edge.


ruinexplorer said:


> You should see if you can get two projectors as a demo and see how the image looks.



I don't know any place where I can get two projectors to test the image in Seattle. Maybe you have any references?


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## Vitaliy (Sep 24, 2012)

museav said:


> The projectors do not create that clean an edge, one reason why you see front projection screens with non-reflective borders. You can probably make what you are considering work well enough to get an image, but you're likely to have some noticeable issues at the center and really wonder if it might not be acceptable and much simpler with a single image.



What we'll probably end up doing is what ruinexplorer suggested. That way, we have a shot at the original plan but also have something that won't sacrifice too much -- a seam in the middle to cover up the unevenness in the middle.


museav said:


> I'm not sure that you understand the issues regarding setup and maintenance. To have a clean transition where the two images meet you are talking about getting 800 0.078" high pixels from each projector to line up with one another other with their edges exactly meeting and doing so with projectors with a fixed short throw lens, no lens shift and limited geometry correction. If you can get that to work then you are also looking at changes that occur over time, movement in the mounts, etc. meaning having to readjust the projectors. In general, you are almost certainly looking at much greater setup and ongoing maintenance than if it were simply two projectors independent of one another.



Are you mentioning that mounts will move around over time, even though they're tightened? Or is the building ceiling, in this case, that you're talking about?


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## Vitaliy (Sep 24, 2012)

cpf said:


> Another option for the dual-projector scenario is giving up on having a semblance of 1 continuous image and just putting a thin-ish strip of masking down the center that's just enough to hide the spill. When running content across both "screens" people might notice it at first, but if the show is so boring that people are left to contemplate the setup of your projection, you have bigger issues.



What about when we have, let's say, a red background color? The yellow in the photo is just a rendering example that I did. We plan to be able to change colors.

Or were you talking about just hiding the rough join in the center with tape and having it be thin enough for no one to notice?


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## museav (Sep 26, 2012)

Vitaliy said:


> Are you mentioning that mounts will move around over time, even though they're tightened? Or is the building ceiling, in this case, that you're talking about?


All of the above. Buildings settle, mounts shift and both move with changes in temperature and humidity. That may or may not become an issue, but don't be too surprised if it happens. Another thing people often overlook, the optics of a projector lens can change as it heats up and cools down and for critical applications such as edge blending or matched images you may want to turn the projectors on in advance and let everything heat up to a nominal level.

Also consider that lamps may not age exactly the same, electronics can drift and so on, so if you really want the two images to match in terms of color and brightness then not only will you have to do a fairly comprehensive initial setup but you will likely also have to routinely tweak one or both of the projectors' settings.


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## Vitaliy (Sep 29, 2012)

museav said:


> All of the above. Buildings settle, mounts shift and both move with changes in temperature and humidity. That may or may not become an issue, but don't be too surprised if it happens. Another thing people often overlook, the optics of a projector lens can change as it heats up and cools down and for critical applications such as edge blending or matched images you may want to turn the projectors on in advance and let everything heat up to a nominal level.



Although what your saying is true, won't these shifts be too subtle to notice immediately? If we had to re-adjust the projectors once a month, that wouldn't be a problem.

Also, if we were to do what gafftaper suggested, there would be even less of a problem because of the frame in the middle.


museav said:


> Also consider that lamps may not age exactly the same, electronics can drift and so on, so if you really want the two images to match in terms of color and brightness then not only will you have to do a fairly comprehensive initial setup but you will likely also have to routinely tweak one or both of the projectors' settings.



That's what I'm currently wondering. In our main sanctuary we recently installed new projectors (in fact the ones that I made a thread about because of problems with them). It has been about 2 months, and there is a slight variation between the left and right projector images, as the left one seems to be a tiny bit brighter than the right. It's nothing that a normal person will notice, but if I turn off all the lights and tell someone that the right projector is less bright, they will see and agree.

As for the electronics, we're going to buy DLP projectors, and since this is "digital" projection, technically we shouldn't have any problems on the electronics part.


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## museav (Sep 30, 2012)

Vitaliy said:


> As for the electronics, we're going to buy DLP projectors, and since this is "digital" projection, technically we shouldn't have any problems on the electronics part.


The projectors being 'digital' will not eliminate the potential issues. The simple fact is that getting multiple projected displays to match in terms of pixel alignment, color, brightness and so on can be challenging to initially obtain and require periodic if not almost constant adjustment to maintain. And as you noted, the closer the displays are to one another, the more visually obvious any difference between them. Of course the displays matching is going to be more critical in some applications than others.

One factor is that there is going to be some variation in initial lamp and light engine output even within factory specs. Another is that the lamps are going to age differently, lamps start losing brightness almost immediately and the rated lamp life is generally an estimate of the hours of use to when the lamp would typically be expected to provide half the initial brightness. However, a number of factors other than just hours of use can affect how the lamp ages such as whether the total use consists of fewer long periods of use or more short periods, filter care, allowing the projector to properly heat cycle when turned off or not, environmental conditions and so on.


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## ruinexplorer (Sep 30, 2012)

Vitaliy said:


> Although what your saying is true, won't these shifts be too subtle to notice immediately? If we had to re-adjust the projectors once a month, that wouldn't be a problem.


I have three projectors with a stacked image (one on top of the other to achieve greater brightness) and have to adjust the image a couple times per week. I check them daily, always allowing for at least fifteen minutes for the units to warm up before I touch them at all. Granted, my projectors have lenses that move and the heating/cooling can make them shift day to day, but it is a lot easier to re-adjust them than it will be with fixed lenses. Depending on your content, a one pixel shift could be very noticeable or completely imperceptable. By framing the images or somehow putting a physical masking between them, the eye will be tricked into not noticing slight imperfections.

I highly recommend that you check out Da-lite's education series (you don't have to read them all) before doing your installation. It will help you choose your materials and understand how to create a great image.


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## Vitaliy (Oct 1, 2012)

museav said:


> The projectors being 'digital' will not eliminate the potential issues. The simple fact is that getting multiple projected displays to match in terms of pixel alignment, color, brightness and so on can be challenging to initially obtain and require periodic if not almost constant adjustment to maintain. And as you noted, the closer the displays are to one another, the more visually obvious any difference between them. Of course the displays matching is going to be more critical in some applications than others.



Well, what this screen is for is mostly worship, which consists of a background and lyrics on top. I'm not sure that for this application it always needs to be perfectly aligned pixel-to-pixel, but I do acknowledge that adjustments are going to be needed, and that colors, contrast, and brightness will probably pose a problem.


museav said:


> One factor is that there is going to be some variation in initial lamp and light engine output even within factory specs. Another is that the lamps are going to age differently, lamps start losing brightness almost immediately and the rated lamp life is generally an estimate of the hours of use to when the lamp would typically be expected to provide half the initial brightness. However, a number of factors other than just hours of use can affect how the lamp ages such as whether the total use consists of fewer long periods of use or more short periods, filter care, allowing the projector to properly heat cycle when turned off or not, environmental conditions and so on.



Yeah I've actually seen that in action with our other projectors downstairs. There is a difference between the two, although they were used together each time.


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## Vitaliy (Oct 1, 2012)

ruinexplorer said:


> I have three projectors with a stacked image (one on top of the other to achieve greater brightness) and have to adjust the image a couple times per week. I check them daily, always allowing for at least fifteen minutes for the units to warm up before I touch them at all. Granted, my projectors have lenses that move and the heating/cooling can make them shift day to day, but it is a lot easier to re-adjust them than it will be with fixed lenses. Depending on your content, a one pixel shift could be very noticeable or completely imperceptable. By framing the images or somehow putting a physical masking between them, the eye will be tricked into not noticing slight imperfections.
> 
> I highly recommend that you check out Da-lite's education series (you don't have to read them all) before doing your installation. It will help you choose your materials and understand how to create a great image.



Thanks for the recommendation. I will definitely look into that if we continue on with this plan.

Are there any short-throw projectors with lens shift? I've looked around and couldn't find anything, but maybe you know something?

As for content, I want to clarify on that. We will usually use this screen to present lyrics over some kind of background. Usually we use abstract backgrounds and not anything that requires a perfect pixel matchup. Once in a while (about once every two months), our youth has a movie night. I'm guessing that we'll want to pay close attention before a movie night, because any offset will be more noticeable than when presenting just lyrics.


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## Vitaliy (Oct 1, 2012)

Do you guys think that there is no way that this will be a reasonable setup? If not, I will start to change the design to something else. I'd really love to have this screen work out, but it looks like either it's going to be too troublesome or not going to work out at all. 

I really like ruinexplorer's idea about creating a frame or a strip in the middle, but I'm not sure how it'll look when we present a video or have a movie night. What do you think it'll look like during videos?


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## ruinexplorer (Oct 1, 2012)

For regular service, the seam will be ignored. With a movie, it might be distracting. Depending on how thick the division is and the distance to the nearest audience member (and how visually picky they are), it may be acceptable. Look at these two pictures, which are essentially video walls, not large screen projection, which shows different bezels. View attachment 7797View attachment 7798

The smaller the bezel, the less noticeable and the sooner you will forget it is there. However, if the movie isn't completely riveting, then your audience will probably notice the divider.

There are projectors which you can have lens shift and a short throw lens (not ultra short throw) but you will dramatically increase your cost per projector. Also, with this style projector, you will need your projectors to be mounted as close to the center axis of the screen as possible, which can present a challenge with "hot spots", especially if you have a high-gain screen. With the ultra short throw, or other fixed position lens, they are generally made to sit off axis, which will help you avoid the noticeable hot spot.


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## museav (Oct 1, 2012)

Vitaliy said:


> Do you guys think that there is no way that this will be a reasonable setup? If not, I will start to change the design to something else. I'd really love to have this screen work out, but it looks like either it's going to be too troublesome or not going to work out at all.
> 
> I really like gafftaper's idea about creating a frame or a strip in the middle, but I'm not sure how it'll look when we present a video or have a movie night. What do you think it'll look like during videos?


I seem to have recently been seeing a number of "we put in two new projectors a year ago and now the images look noticeably different" discussions lately so that is probably making me more sensitive to issues related to differences in the images/ The difficulty is that what differences are noticeable. much less acceptable, can be so subjective and so dependent on the situation. I have also found that sometimes how you envision using projection may not be how it is used once it is installed much less a couple of years later.

For videos and movie night the aspect that jumps out to me is that with the dual projector setup a 16:9 or 4:3 video image would seem to use just over half half of the total screen width for 16:9 images and less than half for 4:3 format images. If you are running a DualHead2Go and using the computer for DVD or Blu-Ray playback then you might be able to move the playback window to one screen but you still have the rest of the computer image on the other screen, otherwise you'd seem to have a centered image with black to either side and the 'seam' in the middle.

You might also have to consider the 'seam' in your other images, not necessarily in the backgrounds but in relation to any text. Think a bright "I" in the center of the screen on a dark background, how would that appear with the center 'seam'? Just something you may have to consider when preparing graphics. Not nearly as critical but it reminds me of a project I did some years ago for the FAA where they noted that individual planes could be just a few pixels wide in the images and thus any seam or mullion more than a pixel or so wide could make it look like a plane disappeared, the point being that it may not be a matter of the absolute 'gap' the seam represents but rather how it affects what is being presented.


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## Vitaliy (Oct 3, 2012)

Just an idea, but what if we overlap the two projectors by an inch or two in the middle, and then shift the left/right images digitally to the left/right, respectively? Either way, because of the constraints of the design, we have extra on both sides that was originally to be absorbed by felt or something.

That way, if we notice that there is some kind of gap or overlap between the two images, we just simply shift digitally to as close to a seamless image as possible. Same thing can be done for the top and bottom as well.

I've looked up the manual for these projectors, and they do in fact have digital image shift.

What do you guys think of this? Will the fact that projectors cannot project "total black" create a noticeable increase in brightness in the middle during a movie in a dark scene, with all the lights turned off?


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## Vitaliy (Oct 3, 2012)

museav said:


> I seem to have recently been seeing a number of "we put in two new projectors a year ago and now the images look noticeably different" discussions lately so that is probably making me more sensitive to issues related to differences in the images/ The difficulty is that what differences are noticeable. much less acceptable, can be so subjective and so dependent on the situation. I have also found that sometimes how you envision using projection may not be how it is used once it is installed much less a couple of years later.



Yes, I know what you're talking about. The audience that is going to be looking at this screen isn't particularly "picky". In fact, I doubt that even three-quarters of them will never know that there are two projectors making up the image, if we were to continue on with this.


museav said:


> For videos and movie night the aspect that jumps out to me is that with the dual projector setup a 16:9 or 4:3 video image would seem to use just over half half of the total screen width for 16:9 images and less than half for 4:3 format images. If you are running a DualHead2Go and using the computer for DVD or Blu-Ray playback then you might be able to move the playback window to one screen but you still have the rest of the computer image on the other screen, otherwise you'd seem to have a centered image with black to either side and the 'seam' in the middle.



Yes, I was planning for that. I thought that this wouldn't play a large role, because when all the lights are turned off nothing but the now "16:9" screen is visible in the middle. I'm just wondering how bright will the gray be on both sides of the unused space during movies (since there aren't real blacks being projected).


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