 I'm Andy, I'm here for GLS lighting, I'm the crew boss responsible for lighting the stages. What type of lights do they use on the main stage? On the main stage we have a mixture of dimmed lighting sources, we have parkans primarily, which is a good old rock and roll favourite, and moving lights, which are now colours and positions that are mixed and moved by remote control. So there you go, that's inside of these lights. So what you've got in here is dichroic glass plates, which affect the colour of the light. So you can mix three different colours, so you've got a CMY colour mixing system, so you've got cyan, magenta and yellow. The lamp's at the back, light comes up through the focal path. You've got that there, next up, you've then got an effect to actually break the light into beams there. A shutter, so you can actually mechanically make strobe effects of shutters. Then moving up to the top, you've got a diffusion, so you can soften the beam. All of that is actually movable, so you focus the beam like that. And then finally on top, you've got a steamed up lens. What are the power requirements for this lighting rig? Each parkan requires one kilowatts of power. We're probably looking at the best part of 80 kilowatts overall, 300 amps, maximum pull, which is the part to respond to generators. That's the same power requirement as more than 40 houses. They use a lot of power as they have a lot of lights. In this set, there are 48 parkans and 16 moving lights. Probably looking in the region about 60 channels of control. The weight of the rig is a factor that needs to be considered. In this particular structure, we know we can take one tonne per arch, so obviously you can't exceed that. The trusses we have here, they're not really that heavy by normal standards. Each fixture that you look at, so the big square lights, you'll have 40 kilos per light for those. Six lamp bars, you'll have 35 kilos per trusses in the rigging itself. So you look at another 40 kilos per hoist for a piece of trusses and another 30 kilos. And then you just add it all up. We're spending tons and tons of equipment above people's heads. So whatever we do, and again we put in hundreds of amps of power in the locality of people. It's all about knowing what we're doing really, about safety and knowing what we're doing. This afternoon the lights will be powered up. They'll need to be put into the right sequence so they can be controlled correctly. Obviously we'll make sure it all works before we send it up in the air. The team have to check extensively that the lighting rig is safe and secure before they hoist it into the air. Andy and his team are qualified to deal with both the power and the rigging, which are essential to their light show. Then we have to wait for darkness. Once it gets dark they all need to be pointed and actually made so it looks like a light show. And then the programming begins. So it can be hours and hours spent overnight being cold and lonely in a tower. While everyone else is asleep while enjoying a drink somewhere else. Making the show. But it's not Andy who's cold and lonely on this stage. Just trying to guess where the lead singer is going to stand. I reckon it's about there. He's still up there. We went to like a drama school, like a theatre lighting course basically, which is a bit different to this kind of thing, but everything about it's the same kind of principle. So that's how I met him. And regretted it ever since. The ones we're focusing now are sort of really rock and roll kind of lights. So they're what you kind of expected of them. The work courses. To be honest it's all about the haze. Without haze it's nothing at all. If you didn't miss the air you wouldn't see it. All you'd see is sort of the coloured dots moving or the patterns on the floor. It's the haze that gives you the beams of light basically. That's where it's, that's a secret. These are all like they say they work us and they do look good. But when you see some of the moving light effects they'll do some pretty nifty stuff. Each one is probably £4,000 each. So you'd expect quite a lot of fanziness. And they do do their job really well actually. If you just do, it's just simple. Mark works at the lighting desk and can call up lighting changes with the touch of a few buttons. So by hazing the air and putting the goba in this is where you get sort of beams of light. But it is all about the haze. How does Mark's lighting help to create a mood for the music? You can't go wrong with sort of blue sort of backlight. And that's like really sort of moody anyway. So that's why there's like quite a lot of blue in the back of this. The sort of festival is kind of like quite hippy. It's kind of quite chilled out. But the actual moving lights will give you any colour you want. You can basically mix them until you get shade you want. It's great. This is the boring bit but it has to be done. Having worked all night setting the lights it's the day of the festival and the lighting team are settling in for a long weekend ahead. How are you two doing? Are you ready to go? We are. Oh you should never do it without a hammer. It's all about the chilliness. First band's on in... What time is it? 10 minutes, near 5 minutes. Now it's just a case of waiting till dark. In the day it's kind of you have to use lighter colours really just because you can't really see.