LED signs at FIFA World Cup arenas - Page 1
Forum section: electronics / general

author: Richard Crowley
author_rank: Super Contributor
timestamp: June 24, 2014, 06:09:06 pm
content: Wow, those LED signage "fences" around the world cup playing fields are remarkably high contrast for sitting out there in the direct morning sun. From the normal viewing distance (across the field), the deep black background is particularly impressive, IMHO. Its one thing to have good brightness, but the contrast seems extraordinary to me. And some of the images have subtle background patterns that come across nicely. Obviously, someone has done their homework on optimizing gamma curves, etc.

author: theatrus
author_rank: Frequent Contributor
timestamp: June 24, 2014, 07:22:34 pm
content: Getting high contrast when there is 0 leakage is not hard (in fact it would effectively be infinite). I think the key is building the assembly where there is little reflected light while pushing a lot of power

author: miguelvp
author_rank: Super Contributor
timestamp: June 25, 2014, 07:29:03 am
content: Are there LED signs? I thought there where RF signage that the camera can capture and then change the advert so they can localize it depending where you are watching it from.Maybe they are just LED signs

author: Psi
author_rank: Super Contributor
timestamp: June 25, 2014, 07:33:06 am
content: I've noticed quite a few fails with LED signage.Designers not understanding just how intense a high wattage 1mm x 1mm point source is.It was crazy when we first got LED traffic lights here, the intensity was so high you kept wanting to look away. Not the best thing for a traffic lightLuckily they installed diffusers and that solved the issue.But yeah, for the world cup signage i suspect miguelvp is right. They're probably just a special grid pattern, qrcode or green screen style thing with the ad overlayed in realtime by computer.Anyone seem the field in real life?Edit: no, it seems they are real LED signs. I guess when you have that much money...

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 25, 2014, 07:48:10 am
content: That might actually be a reason for me to watch a bit of a game...On some sports events you can sometimes see the scanning pattern of signage on slow-motion replays where they've used high framerate cameras

author: bookaboo
author_rank: Frequent Contributor
timestamp: June 25, 2014, 08:07:57 am
content: I have to say they do look really great. These one's look like a P8 as opposed to the usual P16 and appear to have the rubber mask over the front to prevent damage by impact. There's still quite a few dead pixels on the close ups, they are not as clear from the normal view angle (All LED screens have more dead pixels than your eye perceives from distance).There's no interlacing at the slow mo speeds either.I'd love to have the contract for some of those perimeter signs, I bet they have to replace dozens of modules after every game. I just can't imagine an LED sign module not being damaged by a well hit shot.

author: amyk
author_rank: Super Contributor
timestamp: June 25, 2014, 12:32:52 pm
content: Quote from: bookaboo on June 25, 2014, 08:07:57 amGiven that the players are not going to be aiming for the signs, I don't think they'll get as much impact as you think. I haven't watched all the games but I haven't seen the ball go into one yet.However, they probably are the cheapest Chinese LEDs that they could get, since they don't have to last all that long...

author: bookaboo
author_rank: Frequent Contributor
timestamp: June 25, 2014, 01:41:47 pm
content: You obviously haven't watched England's games then !Joking aside they get quite a bit of impact behind the goals, remember these signs are just potted PCBs, there's nothing but a plastic (maybe rubber on these) mask over 5mm of potting compound, you can actually touch the LED from the outside on any of them.As for the LED choice, it's probably Epistar at the very least. It doesn't look like they have skimped on these. Besides it's rarely the LED that dies in these, more likely the ps or driver chips.

author: Jeroen3
author_rank: Super Contributor
timestamp: June 25, 2014, 01:49:03 pm
content: Quote from: amyk on June 25, 2014, 12:32:52 pmDon't forget those led panels are fifa's source of $$$. If they die 5 min in game, 85 minutes of wasted ad dollars turn into smoke.And they probably die on the solder joints, even potted this is a weak spot.