# Rear Projection Drop Help ???



## hammerhorn (Nov 21, 2009)

I am a volunteer at a local theater. I am a fairly experienced digital artist and am trying to figure out a way to possibly help this theater out. They have a ton of old drops and they are going to fall apart soon... some of them already are. I am in the process of re-creating all the art for the backdrops digitally for them just because I love what they do for the community but I'd like to know if there is a projection solution for the following:

array of ultra-short throw (roughly 4 feet from drop space) projectors that can have a hardware or software edge-blending capability. 

I'd need to be doing this rear-projection, with this array mounted to the back theater wall.

I've used a software called "watchout" in the past where we did edge-blending with some gargantuan projectors but it was all front-projection and this was a good while ago. I'm sure there is better technology but you guys out there might be able to assist me. 

I figure helping these guys out, if they are willing to sell some of these really old drops instead of letting them turn into dust, will give them enough cash to buy the equipment to keep them running for the next ten years and also give their old theater hands, who are also volunteers, a rest they need.

ANY HELP would be tremendously appreciated!


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## museav (Nov 21, 2009)

I'll try to address one issue at a time.


hammerhorn said:


> array of ultra-short throw (roughly 4 feet from drop space) projectors that can have a hardware or software edge-blending capability.


You can make the throw any distance you want, the problem is what size image that creates. So without knowing the desired overall image size, including some reduction in the overall image due to overlapping for edge blending, it is impossible to assess whether it is feasible (a good introduction to edge blending can be found here, ftp://ftp.tvoneftp.com/tutorials/edgeblending_inavate_mar08.pdf). As noted in that document, the array would need to be aligned and adjusted from time to time so someone at the theatre would need to be responsible for that. 


hammerhorn said:


> I'd need to be doing this rear-projection, with this array mounted to the back theater wall.


Consider that you also may need some ventilation and/or cabling space behind the projector. And that you need to access them for service. And that a large rear projection screen at stage level is subject to damage not to mention being washed out by stage lighting.

So does it have to be rear projection? What about something like a LCD display array? NEC and Barco offer 46" diagonal LCD panels made specifically for video wall applications that have virtually no bezel, I believe the NEC also has integrated array processing for up to a 10x10 array of panels (no external processor required, just DA the signal to the panels and set it up in their setup menu). And several pro LCD display display manufacturers offer panels of various sizes with thin bezels and integrated array processing. A DLP or LCD video wall, either lamp or LED lit, is another possibility and with a rail system for access would fit within the 4' depth. Just a thought on some different options.


hammerhorn said:


> I've used a software called "watchout" in the past where we did edge-blending with some gargantuan projectors but it was all front-projection and this was a good while ago. I'm sure there is better technology but you guys out there might be able to assist me.


Actually, Dataton WATCHOUT is one of the more powerful display processing packages available and can work with any type of display. Vista Spyder is another popular video processor, but both of these are capable of much more than simply edge blending an image across multiple displays and as such are also typically rather pricey for just that use. Some projectors feature integrated edge blending functionality, but they are usually higher end projectors, and there are other hardware and software solutions out there if all you are doing is edge blending.


hammerhorn said:


> I figure helping these guys out, if they are willing to sell some of these really old drops instead of letting them turn into dust, will give them enough cash to buy the equipment to keep them running for the next ten years and also give their old theater hands, who are also volunteers, a rest they need.


That may be a bit wishful thinking. You are talking probably tens if not hundreds of thousands of dollars for the projection or display hardware and installation. And ten years definitely means lamp replacements, which with arrays often means replacing all lamps at once in order to maintain a consistent appearance, as well as most likely some projector or display replacements. I'm not trying to discourage you from considering the idea further, but a 'digital flat' approach, especially with limited depth available, is often more involved and expensive than people initially think.


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## ruinexplorer (Nov 21, 2009)

It's been a couple of years since I used Spyder, but at the time it only offered horizontal edge blending. We used Axon media servers when we needed vertical edge blending. Watchout is still a very powerful tool and would probably serve you well. As Brad said, there are many challenges ahead of you.


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## SHARYNF (Nov 22, 2009)

It might be well worth seeing what needs to be done to conserve the drops, in the long run it might be a more economical approach, and since it is one by one you might be able to fund raise a bit at a time

As Brad has said, trying to set up a projection system to replace them is going to be extremely expensive. I would suggest that as a partial solution would be to get a decent digital camera and try to get a good resolution shot of the entire drip and then a series of shots that could be stitched together or what ever in the future. This way you have the "original" digital files that as time goes on might be able to be used in a semi economical way

My suggestion if you MUST go with projection, is to forget about edge blending at this point and look at a design of the images that a series of non overlapping projections could possible work, it will not be the best, but might be a starting point


I would think that with a large number of drops you might be able to get someone who knows how to protect and preserve these could teach you what to do. If they are torn, then adding a rear patch of muslin could be an option. With no knowledge of exactly what the problems are, I would guess that you are probably getting cracking and flaking around folds. On e approach which might make storage an issue initially would be to get some PVC pipe that you could roll these onto 

Again with more understanding of the problem, you might get some better suggestions

Obviously taking an inventory of what is what what the images are, condition etc etc would be a good first step

Sharyn


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## hammerhorn (Nov 23, 2009)

Well... there are about 70 drops primarily painted in the 1880's and most or masterworks of art. To just refurb or repair them cost roughly around 25k per drop. To recreate them as traditional drops would be at least that cost and slightly less for a digital print to muslin or something of that nature.

I know that these things are insured for a fortune but it might be better off them or some of them and then vaulting the rest of them. Digital drops are a much more flexible way to go. I am aware of the possible price tag of my guesstimate of about 30k to set back up with a new digital drop perspective.

The throw distance would be roughly about 4-6 feet. With a drop roughly about 30' by 50' wide... i'm still trying to understand what type of array or projector would best meet their requirements. Any additional thoughts?


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## coldnorth57 (Nov 23, 2009)

This the cloasest you will get to what you want BUT it is a small unit

Sanyo PLC-XL50
Ultra-Short Throw XGA Projector


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## BillESC (Nov 23, 2009)

Do you have a proposed budget?

For the cost of multiple projectors, software and RP screen of your required dimensions, you could probably get a Soft LED Video screen. With pixel densities don to 20mm it's just about hi def.


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## SHARYNF (Nov 23, 2009)

My suggestions would be
First Priority, consult with an expert on how to keep them from deteriorating any more, so conservation

Second, get them transfered over to a high quality digital image, so that at least you have captured what you have at this point, and depending on what you do in the future you at least have a starting point

The Problem with projection is always working with the existing stage lighting, Drops are tupically designed to be lit, and so when you just try to project them IMO they may or not work 

It is possible to get digital images transfered over to a non woven or poly film for a lot less than 25 grand each, and they are done in sections that are taped together. From what I have seen they will run about a grand each done in China from a digital image file


Digital Printing Services for Theatrical Backdrops, Murals, Exhibits

Digital Printing Services from Rose Brand

Conference, Stage, & Theatrical Backdrop Printing Magic Vinyl Printing

While not a perfect solution, it might be a starting point for the drops you want to use. 


I am not the expert on led displays, Bill will know a lot more on that .and the cost

I would say that to get a decent high lumen image on a screen from the very short distances you are needing will cost you probablty 600=-750 grand (you are looking at probably 4 Christie projectors with the needed image processing and lenses.

Sharyn


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## BillESC (Nov 24, 2009)

A 30' x 50' drop is approximately 167 square meters. A Soft LED Screen of that size w/2500 pixels per sqare meter would run you about $ 350,000.00 What you could do with it is unlimited.


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## museav (Nov 24, 2009)

BillESC said:


> A 30' x 50' drop is approximately 167 square meters. A Soft LED Screen of that size w/2500 pixels per sqare meter would run you about $ 350,000.00 What you could do with it is unlimited.


I get that 50'x30' would be 15.24m x 9.144m or just over 139 square meters. At 2,500 pixels per square meter, which is 50 pixels per meter, the 348,386 total pixels for that image area may at first appear impressive. However, that's actually a resolution of only 762x457 for the entire 50'x30' image. That could be limiting and may or may not be acceptable for a digital back drop, it certainly would not have the detail of a painted drop.

Bill, is that $350,000 for the screen only or does that include any required processor/controller?

The depth apparently available behind the screen appears to make rear projection rather impractical. Even if it is a 4' throw distance, the distance from the end of the lens to the screen, and not 4' overall depth, the limited depth and large image size seem to equate to needing probably 100 or more projectors. Add to that the supporting structure, required image processing and related setup and adjustment as well as the ongoing adjustments and maintenance to maintain a consistent image. It might work, but how practical it would be is questionable.

In addition, projectors or video walls will also involve some potentially significant power requirements, a soft LED display of the resolution noted may reduce those to a more manageable level but would still need to be addressed.

I also agree with Sharyn's comments regarding lighting. If nothing else, using a digital drop with the image source behind the stage creates a varying and potentially rather bright back light that has to be considered.


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## BillESC (Nov 24, 2009)

Bill, is that $350,000 for the screen only or does that include any required processor/controller?

Although a quick estimate, it is all inclusive.

The spacing of pixels is 20mm


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## museav (Nov 25, 2009)

BillESC said:


> Although a quick estimate, it is all inclusive.


Thanks for clarifying that.


BillESC said:


> The spacing of pixels is 20mm


Or just under 0.8" and about 15.25 pixels per foot.


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## BillESC (Nov 25, 2009)

Brad

For calculating the cost of Soft LED Screens (since they are made to order,) plan on $ 2100.00 per square meter. This includes video interface, cables, ATA road case and shipping to the US.


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