# Video display options



## LightBug (Dec 19, 2013)

Hi all, we are a small production just trying to make something a little fun for spectators. We are looking to make a 10x10ft box and use either a projector, tv wall, or led wall(which is looking unlikely due to cost).

Understanding the basic pros and cons and keeping costs in line we have found we could either;

A: Build a projecter screen with Dazian Backlit material and buy a used projector for around $500-$600 or new for around $1,200 new with around 4000 lumens

B: Buy some vizio style narrow bezel screens. They have a TV model now that would be great except the lower right corner has some stupid protrusion coming out of it, so we'd have to go for some samsung models with slighty bigger bezels. The screens come in around $100-$300 a piece depending on size.

C: Slowly amass a video wall over time as the price per sqft is higher than the other two options. On ebay some seller from china sells 128x128mm panels for a decent price compared to name brands, but not sure how well they could be trusted so I am hesitant to pull the plug on it even for testing.

Projector route would be cheapest per sqft, but I am worried about always replacing lamps and/or ambient light always being a problem.

TV wall is a bit pricier per sqft and more of a pain to set-up and more delicate to handle(for screen protection) but contrast ratio would be nice and ambient light would be less of an issue, we also wouldn't have to worry about lamps or projectors going down. But since we won't be able to afford the bezel free, video wall specific tvs, we'd have to witness the the dreaded lines in between each screen.

LED wall is very pricey even with the off brand Chinese models and seems like you get laughable screen area per panel for the money. The pro of course would be easier to throw up/take down, no projectors or tv glass to worry about, etc. We would have to slow purchase these over a year or two to have any significant screen size which is why I won't really consider this option as it's currently to rich for our blood.

What we're trying to do is build a little entrance area for boxers, pro wrestlers, MMA, etc to walk through and have a screen of decent size to feed live video for people to see during fights and to display graphics, sponsors/advertisers, etc onto during downtime. Furthest seat will be roughly 150' away from the screen. During the fights or wrestling, the entrance would be relatively dark as well as the audience seating areas. Mostly just the ring will be lit during any action.

If given these options what would be better over the long haul? We'd like to keep this setup for years to come, so we'll be stuck with whatever decision we make for years to come, which is why I'd to love get some advice from experienced people so we don't end up hating our lives after the purchase.

Thanks for any advice you give


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## techieman33 (Dec 20, 2013)

I would go for the projector option. Lamps aren't that expensive on a projector of that size, and they usually have pretty long lives, usually in the 2000 hour range. Buying video wall peice by piece is almost always going to turn out badly, especially if the only stuff in your price range is the low end chinese imports. Colors will never match quite right. And with the chinese stuff they could change something in the design at any moment and the newer panels could not attach correctly to the older ones. Getting tech support, and replacement parts could be next to impossible as well. The same goes for using monitors or tv's. You never know when a model will go out of production and getting a replacement panel could become nearly impossible a few years from now. Rental is always an option too, especially if you don't do that many events each year.


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## MNicolai (Dec 20, 2013)

Be warned that inexpensive consumer-grade displays aren't all they're cracked up to be. For example:

+ They're harder to control (no RS-232)
+ They are quickly discontinued as new models come on the market (almost every time we design a video system, the displays we chose our discontinued by the time the contractor goes to install them)
+ They can be known to come with warranties that specifically state they are for residential use only and use of those displays in a commercial environment will void the warranty.

I've had too long a week to draw up a more comprehensive response for you than this, but I thought you should know what an inexpensive display really gets you, which for the most part is headaches in our experience.


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## LightBug (Dec 20, 2013)

Appreciate the advice guys. MNicolai No worries here, had a long week myself, know all to often how that goes lol. 

I Just have 2 more quick questions about the projector route.

1. Should 4000 lumens be sufficient for what we want to do and given we'll have some basic control over the ambient light? At 6,000 Lumens the prices really start to jump up, even for consumer brands.

2. Should we shoot for a used Christie or other commercial designed projector or a new consumer-based model? I have heard projectors can get dim when they age even after putting in a new lamp, so that has me a bit worried going the used route.

I just want the screen to have enough punch to look nice, bright, and have decent color, etc. Don't want to spend on more lumens then we'll need if we can help it.


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## techieman33 (Dec 20, 2013)

LightBug said:


> Appreciate the advice guys. MNicolai No worries here, had a long week myself, know all to often how that goes lol.
> 
> I Just have 2 more quick questions about the projector route.
> 
> ...



None of us can tell you what will be a powerful enough projector. Your going to have to decide on a screen size then rent or demo a couple of projectors to see what will and won't work.


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## LightBug (Dec 20, 2013)

Okay, I will call some places tomorrow to see about demoing a projector and see what we can figure out. Thanks again


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## museav (Dec 20, 2013)

I'd like to go back to the size and format. You mentioned a 10'x10' box but is that the actual planned image size? If so then a few thoughts:

That may be a small image for viewing ads, etc. from 150' away. You might want to consider if something like limiting yourself to larger fonts and simple graphics is feasible or supports the intended purpose. 
10'x10' is not a standard video format. A 4:3 format projector would create a 10' high by 13.33' wide image, a 16:9 format projector or flat panel a 10' high by 17.78' wide image. You could block off part of those wider images to use only a 10'x10' area but you would need to a) consider that in producing content and b) for a projector consider that the projector is still creating a wider image and thus the brightness associated with the 10' wide portion of that overall image is only a portion of the full projector output. On the latter, an example is that with a 4:3 format projector the rated brightness would be associated with a 13.33' wide by 10' high overall image area and the brightness associated with a 10'x10' portion of that is thus about 75% of the rated brightness.
 A projector may be the less expensive option but might the depth potentially required and keeping ambient light off the rear projection screen be factors?

On the LED walls, consider the pixel pitch, the resulting resolution at your image size and how close your viewers may be. Many inexpensive options may be a larger pixel pitch intended to be used in quite large displays that will be viewed primarily from a distance.

Do the flat panel displays you are considering support tiling? Some flat panels have integrated support for tiled video walls up to some defined size (4x4, 5x5, etc.) and thus do not require an external processor. However, if the flat panels do not have that functionality integrated in the displays then you may need to provide an external processor. Similar with a LED video wall, the tiles or curtain are required but so is a compatible processor to map the video images to them.

For projection, have you considered using a premanufactured rear projection screen with a tubular frame and 'snap on' material? That seems a good option if you are going to be setting this up and moving it a lot.

Also on the screen, one of the factors in the brightness of a rear projected image in the screen gain or how the screen affects the brightnesss hitting it from the projector. There unfortunately seems to be no related information provided for the Dazian Backlit material you noted and thus no way to predict what the resulting image brightness might be. I'm not sure why many companies offering materials specifically for projection applications don't provide such basic technical information as screen gain.


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## LightBug (Dec 20, 2013)

Hi Museav, thanks for the wonderful reply. To answer some questions.

1. Yes we, intended to make a 10' tall, 10' wide screen, but with accounting for the 4:3 ratio we would have no issues making it a bit wider to collect the full image. We are sticking with 4:3 ratio for the near future. Our cameras support 4:3 or 16:9 but for aesthetics with the screen we'd prefer a more squared shape than rectangle.

2. The pixel pitch we saw on some of those chinese models claimed around 4mm or pixel pitch, but they don't have any pictures of it in action which makes me leary because even wiedamark doesn't seem to have that small of a pixel pitch and they're much more well known. here's a link to one of the sellers items http://www.ebay.com/itm/10x-PH4-RGB...773?pt=LH_DefaultDomain_0&hash=item4844317b15

3. The flat panels would probably not initially support any kind of daisy chaining, however we were going to use some raspberry pi's and control it separately much like a LED video wall has a separate matrix/controller module to control the individual panels. We were looking at off the shelf consumers tv's from 32" to 50" the problem we ran into with this route was very little tv's or monitors today have ultra slim bezels to minimize the bars across the image. Vizio has the almost perfect tv but has logo tag under the right side that makes it useless for stacking. Here's a link to their tv, you can see the bottom right corner ruins it as a candidate for a video wall. http://www.bestbuy.com/site/vizio-m...000032eaecdb&gclid=CJnp3qTOv7sCFfBDMgodskwAKg

There's some other monitor I believe from AOC that was almost perfect as well, ultra Slim on top and sides, but then had a big fat bezel on the bottom portion, plus it was a bit tiny as well(only 27" or so) . As said before we are aware of video wall specific TVs which would fit the bill but would be out of our price range to make a wall of any meaningful size.

I have looked at pre-made screen systems, but none seem to fit our needs, so we're going to just do it ourselves to make sure it's shaped how we want. Most modern screen systems(in fact all that we looked at) are designed specifically for 16:9 and are rectangular. The setup won't be getting moved to often and when it is, it will be very short distances, it will mostly stay in place once setup.


For the view distance, we could go up to 20'x20'(or 20'x26.66), but now I'd be worried about the amount of lumens required to get a clear image out of something that size. I wonder would 4000 lumens even phase a screen that size or would we be left just a barely visible dull image, etc We have some basic control over the lighting. The only "ambient" light that would be on at the same time as the screen would be some colored par cans(source fours), some cheap strobe lights, and I think we may add 2 small moving lights, but that stuff is just for entrance stuff and to add some flash to the athletes entrances and will be off immediately when they get in the ring. We don't have any HBO style overhead lighting grids or anything but lights(house lights) are controllable to dim lights around the seating areas and entrance area leaving just the ring light, so ambient light on the screen should be minimal. This guy on youtube seems to have done a 20ft screen with 2700 lumens, it's not utilizing 100% of the screen, but gives me hope maybe we could get away with a nice 4000 lumen projector as the area would be roughly as dark as that, a tad bit lighter but not by a wide margin. 

I don't know why dazian does that either, I think one of their materials does state 1.0 gain but I will have to give them a call here in a minute and see if anyone there may have an idea on what the spec is on it. I am guessing 1.0 but you never know.


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## museav (Dec 21, 2013)

The Vizio model you noted a good example of one potentially relevant issue in that it normally has a one year warranty for consumer/residential use but for commercial use the warranty is limited to 90 days. A number of consumer displays limit if not outright exclude warranty coverage for commercial/professional use. Between that and consumer models changing so often you might want to purchase one or more spares to have on hand if you went that route.

The image size to me falls into that area of while you have to work with the budget you have, does it make sense to spend that budget on something that you are not comfortable will work as desired or intended? For example, how large can you make an advertiser's logo or catchphrase and will the advertisers accept that result? If not then might you lose that potential income or sales benefit and is that acceptable or might it justify spending more for something that would work?


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## LightBug (Dec 21, 2013)

Museav, great points and that is something I thought about, not so much the warranty(which is a great point) but the constant discontinuing of TV's and then the headache of trying to replace them if one died on us, etc.

So I am at this point pretty settled on a projector setup as we can get the largest screen for the lowest cost. For the screen at least, the material is cheap enough to build any massive display we wish. The projector is what is going to get us in trouble lol.

I can squeeze a used 6000 lumen projector in the $1,200-$1,500 range, and if we did 20'x20' screen that should be plenty big for our needs, and we wouldn't be moving it around too much(especially at that size). I just stress about the projector being strong enough, which is what attracted us to possibly using a video wall(either TV/Monitors, or LED). But projector seems to be overall the most bang for the buck.

NEC list min and max screen size recommendations on their site and at 6000 lumens it says anywhere from 25" to 500" diagonal if we go the 20x26(or whatever the correct aspect ratio would be) we're looking at just a bit under 400". 6000 seems to be our cutoff point, at 8000+ we're looking at 18-20k USD and up, so we will not be able to afford more than 6000 lumens, possibly 7000 if we can find a deal on ebay or craiglist. but 6000 seems more commonly for sale than 7000.

Like I said, I am just worried about the lumens being enough to light a screen so massive(well, too us anyway. I am sure you guys deal with much larger screens all the time). Would you consider 6000 lumen on a 20x20' screen to be workable or are we just asking for trouble with that?


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## museav (Dec 23, 2013)

What has happened is that the focus has shifted much more to image contrast ratio than just image brightness. Image contrast ratio considers both the peak brightness and the black level in an image, with the black level of an image often determined by the ambient light level. That provides a more direct correlation of desired brightness to the ambient light level, which is the unknown factor if you look at just brightness.

That's a way of saying that what brightness you need is typically dependent on the ambient light levels that may be on the screen. You could have a bright image but if the ambient light is almost as bright then the resulting image is going to be washed out and likely unacceptable. Conversely, if you have very low ambient light levels you may be able to get an acceptable image with a much lower projected brightness. This is why guidelines such as the Digital Cinema Intiative define criteria for both ambient light levels and image brightness, by controlling the ambgient light levels they can define a more limited image brightness for an acceptable image. It's also why knowing the ambient light levels expected on the screen is a critical factor in assessing what projector brightness may be appropriate. And why I'm hesitant to say something will or will not work. However, 6,000 lumens over a 20'x20.67' image is 11.25ftL, which is a low image brightness for even cinema type ambient light conditions.

As far as the difference between projectors rated at 6,000, 7,000 and 8,000 lumens, there could be other factors involved in how that relates to any perceived difference. For one, as I previously mentioned, those values would be for the entire projected image and with a 4:3 projector your square format screen would be just 75% of the total image being projected, thus your really looking at what would be 4,500, 5,250 and 6,000 lumens over your square viewable area.

Adding to that are that projectors typically have their brightness rated at their optimal operating conditions and real world operational factors such as lamp life, the lens optics and where you fall in its operating range and so on may reduce the brightness you actually get. Lamp outputs tend to decline with use and thus unless you plan to immediately replace the lamp then since that could be relevant if you are purchasing used. The use on the lamp provided would likely affect the actual brightness you get from the projector and a 6,000 lumen projector with a new lamp may actually be brighter than an 8,000 lumen projector with a lamp with a lot of hours on it.

Then there is how the human eye perceives the differences in brightness. If you had the same image side-by-side with one from a 6,000 lumen projector and one from from an 8,000 lumen projector you might notice a difference. However, if those images were in two different rooms you might have difficulty going between them and noticing the difference.

On the cost of the projectors, the difference may not be just the brightness. You may need to look at what else might be different such as lens options, single versus multi-lamp operation, etc. Also, if purchasing used you want to be sure you are getting a projector with a lens that will work for you. In your situation it might be an unwelcome surpirse to find that you had purchased a projector with an optional long throw lens!


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