# 6 Projectors one image ?



## jeme (Nov 29, 2011)

hi 

I want to buy 6 projectors to display one image ? screen size is: 6m * 10m= 60 sqm

any projector can do this or any other solutions ! please !!

the distance from projectors to screen is: 1 meter !! 

my application is: video show. 

thanks


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## len (Nov 29, 2011)

I doubt there's a lens made that can manage a screen 18 x 30 feet from 3 feet away. 

If you mean 6 projectors that will project part of the image onto that screen, that's still a pretty tall order. Plus, you'll need something like a hippotizer or some other thing that can separate the image into 6 bits, then blend the edges back together once it's hitting the screen. It's been a long time since I was in that world, but I think the software that runs the HES/Barco DL series moving lights could do that. There's probably other stuff by now, but again, I'm out of that world.


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## ruinexplorer (Nov 29, 2011)

What kind of budget are you looking to work with? As len suggests, you will need to split the image and then blend the projectors to gain the full size. At one meter, you are pushing the limits of optical technology, but you could also consider using a first surface mirror per projector to gain additional size at the loss of some lumens. Speaking of which, how bright do you need your image?


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## derekleffew (Nov 30, 2011)

len said:


> ...but I think the software that runs the HES/Barco DL series moving lights could do that. ...


That would be the proprietary Collage Generator™ software. Generically, a feature of most all presentation display systems. See the links in the wiki entry edge blending.


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## jeme (Nov 30, 2011)

hi all, 

many thanks for your replies, 

my budget is around 15 k, lumen per project is: 3500, I'm thinking of short throw projectors !! 

if there are any software or hardware to handle this issue please let me know! 

thanks


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## SHARYNF (Nov 30, 2011)

Are you trying to use 6 projectors to create one image, or Re you using 6 projectors to create on image six times?
Sharyn


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## museav (Nov 30, 2011)

Can we maybe simplify this to asking what you are trying to do and the overall goal?

For example, is there a specific reason for 6 projectors? A 6m x 10m overall image is a 15:9 format but creating that with 6 projectors seems likely to relate to either a 3m x 3.33m nominal image per projector (2 projectors high and 3 wide) or a 2m x 5m nominal image per projector (3 projectors high by 2 wide). Overlap for edge blending will affect that actual projected image size, which would need to be slightly larger, but 3m x3.33m (1.11:1 format) and 2m x 5m (2.5:1 format) don't match up well with any common native projector formats. So is there a specific reason for 6 projectors or might 4 projectors (2x2) or 9 projectors (3x3) be an option?

Ultra-short throw projectors would seem to present several challenges for such an application. They are very particular about their location relative to the image, not just in the distance from the screen but also in the horizontal and vertical relationship to the image, so if you could get the desired image size with the throw distance available that would then dictate a specific position for each projector with little possible deviation. Because of the optics involved, the ultra-short throw projectors are also very limited in image adjustments, which makes them a poor choice for adjacent or edge blended images. Finally, most projectors that might come anywhere close to the throw distance required seem to be limited to 2,500 lumens and in the maximum image size supported.


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## Esoteric (Nov 30, 2011)

Yeah, way too little information here. You don't necessarily need any heavy duty hardware, but you might,so it is hard to tell.

Also I second what Brad said on ultra-short throw projectors. Almost all of them have a slight bow to the image on the sides (because of the mirrors used) and thus are VERY difficult to blend like that. Now, don't take products guides at face value (I often project 9'x12' or larger images with these ultra short throw projectors) and there are some in the 3500 lumen range now, but they are VERY particular. Not to say it cant be done, but it is VERY, VERY difficult.


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## jeme (Dec 1, 2011)

museav said:


> Can we maybe simplify this to asking what you are trying to do and the overall goal?
> 
> For example, is there a specific reason for 6 projectors? A 6m x 10m overall image is a 15:9 format but creating that with 6 projectors seems likely to relate to either a 3m x 3.33m nominal image per projector (2 projectors high and 3 wide) or a 2m x 5m nominal image per projector (3 projectors high by 2 wide). Overlap for edge blending will affect that actual projected image size, which would need to be slightly larger, but 3m x3.33m (1.11:1 format) and 2m x 5m (2.5:1 format) don't match up well with any common native projector formats. So is there a specific reason for 6 projectors or might 4 projectors (2x2) or 9 projectors (3x3) be an option?
> 
> Ultra-short throw projectors would seem to present several challenges for such an application. They are very particular about their location relative to the image, not just in the distance from the screen but also in the horizontal and vertical relationship to the image, so if you could get the desired image size with the throw distance available that would then dictate a specific position for each projector with little possible deviation. Because of the optics involved, the ultra-short throw projectors are also very limited in image adjustments, which makes them a poor choice for adjacent or edge blended images. Finally, most projectors that might come anywhere close to the throw distance required seem to be limited to 2,500 lumens and in the maximum image size supported.


 
thanks all

the issue is:
1- I've a project an outdoor show the screen is a glass 6m by 10m wide
2- I'm using rear projection, the distance between projectors and the glass is 1 meter,
3- I want to play video and live TV.
4- I want to play one image 

any suggestions or help is appreciated.

thanks again


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## museav (Dec 1, 2011)

jeme said:


> thanks all
> 
> the issue is:
> 1- I've a project an outdoor show the screen is a glass 6m by 10m wide
> ...


You have a glass rear projection screen that is 6m x 10m (19.69' x 32.81')? Is it an actual rear projection screen or simply glass? Is the screen potentially in direct sunlight on one or both sides?

How do you envision mounting the projectors? Could the projectors be located anywhere behind or above or below the screen as long as the throw distance is 1m? Is the 1m throw distance based on a specific projector depth and ventilation clearance?

Do you know the actual video signals involved (composite video, component video, VGA, DVI, HDMI, SD/HD-SDI, etc.)? Is latency, delay in the projected image resulting from the video processing, a concern in regards to the live video? For example, are you displaying a live presenter or performance where noticeable delay in the projected image would be unacceptable?


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## jeme (Dec 1, 2011)

museav said:


> You have a glass rear projection screen that is 6m x 10m (19.69' x 32.81')? Is it an actual rear projection screen or simply glass? Is the screen potentially in direct sunlight on one or both sides?
> How do you envision mounting the projectors? Could the projectors be located anywhere behind or above or below the screen as long as the throw distance is 1m? Is the 1m throw distance based on a specific projector depth and ventilation clearance?
> 
> Do you know the actual video signals involved (composite video, component video, VGA, DVI, HDMI, SD/HD-SDI, etc.)? Is latency, delay in the projected image resulting from the video processing, a concern in regards to the live video? For example, are you displaying a live presenter or performance where noticeable delay in the projected image would be unacceptable?


 
museav, 
i do appreciate your help, I'm really grateful !

please see fallowing pictures it may answers some question !



regarding your questions: 

1- the screen " the glass" is covered by a rear projection film.

2- sunlight is on one side.

3- all projectors most be mounted 1 m above behind the screen.

4- I'm playing (composite video and HDMI ) live streaming is linked to TV satellite receiver.

thanks a lot


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## sk8rsdad (Dec 1, 2011)

Does it have to be 6 projectors? Have you considered digital signage solutions, like an array of LCD TVs or LED screens instead of rear projection? If it has to be rear projection, what about dozens of picoprojectors instead of 6 projectors, assuming software can be found to manage the image stitching. The image size and requisite intensity to overcome the sun is quite ambitious for a $15,000 budget.


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## jeme (Dec 1, 2011)

sk8rsdad said:


> Does it have to be 6 projectors? Have you considered digital signage solutions, like an array of LCD TVs or LED screens instead of rear projection? If it has to be rear projection, what about dozens of picoprojectors instead of 6 projectors, assuming software can be found to manage the image stitching. The image size and requisite intensity to overcome the sun is quite ambitious for a $15,000 budget.


 
LED and LCD screens are not welcomed by the client. 

number of projectors is not a big deal but it most be within the budget.

thanks mate !


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## museav (Dec 2, 2011)

Some quick thoughts...

Many of the ultra-short throw projectors are likely not viable since they typically have to be located above or below the image area and you seem to have very limited room above or below the glass.

Most short throw projectors would have to be located at the horizontal and vertical center of the image they create, meaning probably needing to build some framework or scaffolding construction to support them, which may be challenging within the budget.

You can apply a diffusion film to the inside of the glass but that would not seem to affect any glare or reflections from the exterior. You may need a very bright image to overcome that.

Having to address both composite video and HDMI means some more serious processing. And HDMI from a satellite receiver may mean having to deal with HDCP, which many video processors don't address.

I'm really not trying to be discouraging, but it seems a bit like someone defined an application and a budget before verifying the two are compatible. Add apparently having numerous limitations placed on the potential solutions and it seems likely to be one of those situations where you may be able to do something but the result may not be what was hoped for or envisioned. And that "what is acceptable" aspect can be very difficult to address via a forum environment.


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## jeme (Dec 8, 2011)

museav said:


> Some quick thoughts...
> 
> Many of the ultra-short throw projectors are likely not viable since they typically have to be located above or below the image area and you seem to have very limited room above or below the glass.
> 
> ...


 
sorry of being late to reply !

since it's my high season period.

how about if the client increase the budget to 25k ! can I have a solution with this number ?


budget is only for projectors and edge blending equipment or software ! 
film and installation got separate budget !!

thanks a lot


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## JChenault (Dec 8, 2011)

I'm curious why the one meter restriction. As I look at the images, it seems that the window glass is at an angle. Are you planning to build a frame one meter behind the glass to mount your projectors to. If so why is one meter the magic number.

Is that one meter number the distance from the lens of the projector to the screen, or the distance from the back of the projector to the screen?


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## BillESC (Dec 8, 2011)

Just for discussion, BenQ MX812ST projectors will give you an image approximately 4.5' x 5' at one meter throw. At 3500 lumens and 4600 to 1 contrast ratio they might do the job.


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## museav (Dec 9, 2011)

BillESC said:


> Just for discussion, BenQ MX812ST projectors will give you an image approximately 4.5' x 5' at one meter throw. At 3500 lumens and 4600 to 1 contrast ratio they might do the job.


According to BenQ's online calculator, a 3.28' or 1m throw results in a 48.6" x 64.8" image with the center of the lens 7.29" above the top of the image or below the bottom of the image for its native 4:3 format and a 36.45" x 64.8" image with the center of the lens 13.36" above the top of the image or below the bottom of the image for a 16:9 format image. It apparently does not directly support 16:10 or 15:9 formats. It is a fixed lens and has basic +/-30 degree vertical keystone correction capability. The projector itself is 9.9" deep with the power connection and inputs on the rear panel. Street price seems to be $1,050 to $1,100.

The desired image is 19.69'x32.81', with a 4.05'x5.4' image from the projector and accounting for 10% overlap for edge blending that equates to a 6x8 array of projectors. That's $50,400 to $52,800 just for the projectors without any tax and shipping. That's also without any processing that could handle 48 edge blended projectors, which might require 'stacked' processing, i.e. maybe a 2x2 layer of processing and then feeds four 3x4 processors, which would be a large cost on its own. Not to mention the challenges almost certainly to be encountered in getting so many images to align where they overlap when having to work with the 0.6:1 aspherical short throw lens and very limited image control of those projectors.

You could reduce the number of projectors, which would also reduce the associated processing required, but that is then going to require considerably more space to support a longer throw and likely more capable, and thus more expensive, projectors.

I certainly could be overlooking something but for what I understand you are trying to achieve I get the impression that some constraint(s) will have to change significantly, be it the budget, the image size, the throw distance or the acceptance of LCD arrays or LED video walls/curtains.


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