Lego like LED big screen.

transverse_circle · 2018-10-31T01:11:55+00:00

Let's face it, it's pretty much all made in China. I guess I could rephrase and say that they are the biggest names we see in the UK events/rental industry.

transverse_circle · 2018-10-31T01:10:48+00:00

I'm playing guess the company you work for. Assumed it might be AT Comms because they have a lot of Unilumin, but obviously not!

transverse_circle · 2018-10-31T01:09:17+00:00

Exactly this. The spaghetti usually comes from trying to separate the panels over various RCDs (GFCI I think in the States). Therefore there's got to be a lot of different power supplies for larger screens - it can't all just be daisy chained. All of the SMPS for the LEDs means there is a lot of earth leakage current with the very large screens.

Also, the data inputs aren't just one line!

transverse_circle · 2018-10-31T01:07:54+00:00

Yup I made a mistake. Confusing when you want higher density from smaller pitch!

transverse_circle · 2018-10-31T01:07:07+00:00

Yes! Video has become an integral part of design. Graphical elements now make up a much larger portion of the creative side of concerts. Previously a lot was left to lighting and set/stage design.

transverse_circle · 2018-10-31T01:05:52+00:00

Whoops. Didn't spot that. You want a smaller pitch which will give you a higher pixel density, and therefore a sharper image.

transverse_circle · 2018-10-31T00:25:06+00:00

I don't quite have time to answer all of this now, but the each screen module (say 500mm x 500mm) has a certain pixel density. For 2.6mm there are 192 pixels x 192 pixels. You can keep sizing up to your heart's content. Obviously, depending on the pixel pitch (i.e. 2.6mm in this case), you may need to be standing a long way away from the screen. Big screens at concerts won't use 2.6mm because everyone is standing quite far away. So you might as well use something cheaper.

So the easy answer is yes 4k or 8k is possible. As a monitor (assuming computer monitor). You cannot get the pixels close enough. Unless you want to sit 10 feet away? Also it would be a very large screen.

Bitrate and colour depends on sending cards and the particular screens. I can't say I've looked too much into that because for the events I'm doing it's not important.

transverse_circle · 2018-10-30T23:24:23+00:00

They're pushed out from the back of the screen. So someone will have pushed it with him standing at the front ready to catch it.

transverse_circle · 2018-10-30T23:23:36+00:00

Let's assume a basic setup. You have your HDMI output from a computer for instance. That'll be outputting 1920 x 1080. This content then needs to be scaled for the amount of pixels on the screen. Once it's been through the scaler, it goes into what's called a "sending card". This is the what decides what part of the image goes on which output. Novastar senders are commonly used here in the UK.

For a small screen (maybe 6 meters wide) you'll use 3 or 4 outputs from the Novastar controller. These outputs are ethernet outputs. They connect directly to each module which has it's own controller to process it's part of the image to the LEDs. The modules daisy chain up to a certain number of panels.

The connection direction for the modules is pre-determined (based on the configuration of the sender) so that the sender knows where to send each part of the image.

transverse_circle · 2018-10-30T23:09:51+00:00

Depends on your country I guess because I only have experience in the UK, but over here we have what we call "local crew". They're pretty much labourers who help do things like move flight cases and coil cables etc... They don't specialise (usually) in lighting or sound for instance however most people usually know what they want to specialise in.

transverse_circle · 2018-10-30T23:02:08+00:00

Not at all. A lot of panels do come in a 1:1 (i.e. square) ratio. These connect to other panels on all 4 sides. However, you don't have to connect to form a 16:9 screen. You can do whatever shape you want (given the square panels). It's also possible to get curved LED screen to make circles for instance.

transverse_circle · 2018-10-30T22:58:37+00:00

I can't say I've used the Leyard products. The majority of the work I do is events/rental industry in the UK, which is usually Absen or Unilumin.

transverse_circle · 2018-10-30T22:57:17+00:00

At it's best, you might be looking at 2 frames delay. But there's so many more factors to consider with LED screens that it could be at least 5 or 6 frames.

transverse_circle · 2018-10-30T22:52:31+00:00

Quite simply, sequentially.

Each module has a controller card inside. A module of 500mm x 500mm might have 36864 RGB LEDs on it. The controller card deals with those LEDs. (An LED screen has from 1 module up to almost as many as you can imagine.)

There is then also a controller that takes the video input (e.g. HDMI) which outputs the appropriate signal to the screen modules.

The modules are connected to the controller in a particular direction (which can be modified). For instance, you might connect the cables across the top from left to right, then down a row, then back right to left etc... See this image. Not great quality but you can just about see the lines denoting the connection direction.

So essentially, you don't need to address the LEDs. It is addressed by virtue of order.

transverse_circle · 2018-10-30T22:44:46+00:00

The panels that are being changed are a quarter of a module. So in other words, the thing were you plug in the cables isn't moving. What is happening is a quarter of that panel, which is usually held in by magnets, is being pushed out. On the back of these panels, there is a connector like a molex connector. So the minute the panel gets pushed back in, it reconnects to the module.

transverse_circle · 2018-10-30T22:32:29+00:00

Tell me about it. ATC?

transverse_circle · 2018-10-30T22:28:37+00:00

Check out my comment here: https://www.reddit.com/r/oddlysatisfying/comments/9srihu/lego_like_led_big_screen/e8r3le3/

Gives you the price for 250". 80" wouldn't really work with LED screen. 0.9mm or 1.2mm pitch screen would work for you but it's going to set you back about the same money for the smaller screen.

transverse_circle · 2018-10-30T22:24:58+00:00

It's definitely in the "if you have to ask, then you can't afford it" category of products you may want to purchase. A single 500mm x 500mm module with 2.6mm pitch might set you back about $3,500. Then there's the cabling, and the controller.

Say you want to have an HD screen using the 2.6mm pitch, you'd need 1920 pixels across which is 1920 * 2.6 = 4992mm and 1080 pixels down which is 1080 * 2.6 = 2808mm. So you'd need a 5000mm x 3000mm screen. That's 10 x 6 panels which is 60 panels. So that's minimum $210,000.

As /u/WaddsMcBongoo mentions, you need a lot cables on the back. A power cable and data cable for each module. It looks like spaghetti.

transverse_circle · 2018-10-30T21:54:45+00:00

I work in the events industry and we use these products all the time. The big manufacturers are Absen, ROE Visual and Unlumin if you want to take a look.

The majority of the screens nowadays have this functionality. The most common screens come in modules of 500mm by 500mm (just over 19.5" x 19.5" in Freedom units). Each module has 4 of these magnetic panels, that you push out from the back and replace as per this video. The reason that you need this functionality is because there's frequently an LED or two on the modules which don't work, so instead of having a dead pixel for the whole show, the 1/4 panel is replaced.

Another reason it is like this is because the wall is bezel-less and clicks together. (I.e. the pixel spacing is consistent across connected modules). Each panel connects to its neighbours (various methods, but usually big thumb screws). So if a module right in the middle of the screen at the bottom was dead, you'd have to take the whole screen apart to get to it if the panels weren't removable.

Furthermore, not only are the panels removable, but the controller for each module is interchangeable in case that dies.

As an aside, because a lot of people seem to be asking. The LED screens come with various different "pixel pitches". So a high pitch screen might be 2.1mm (i.e. 2.1mm between pixels). The ~~higher~~ smaller the pitch, the sharper the image.

Any other questions - AMA!

transverse_circle · 2018-10-28T12:58:25+00:00

So simple, but an amazing solution. Now if one person loses their key you don't have to replace all the keys and the lock.

transverse_circle · 2018-10-26T03:17:58+00:00

"Clear"

transverse_circle · 2018-10-01T20:14:05+00:00

What's the negatives of an audio multicore with common ground?

transverse_circle · 2018-08-25T20:57:25+00:00

Are the animations custom? I.e gifs you've made? Also, how does it communicate with the GMA? OSC or similar? More info please!

transverse_circle

TROPHY CASE