Torch relay challenge for BBC broadcast output
Now as promised - here's the second guest blog this week about the torch relay and the way it's being broadcast. It's from Imelda Flattery in BBC News, who's been leading the planning of our coverage.
Usually you know where you stand with a big news event. Last year's royal wedding took place at Westminster Abbey.
End of. It didn't up sticks every 10 minutes and set itself alight.
The torch relay is something different. Live events often perambulate at a stately pace over a short distance.
They involve world leaders or Popes waving serenely to the crowd as they pass. Not the relay though. It's relentless.
So how do you provide non-stop live coverage of something that's the duration of about 280 marathons stitched end-to-end?
Conventional TV trucks and outside broadcast vehicles work well at static positions along the relay but each will only give you a short window of coverage. Once the torchbearer has passed you, you're old news.
Helicopter cameras are another option and although we will use them occasionally, flying one for 12+ hours a day for 70 days isn't a cost-effective solution.
A satellite dish on the roof of the vehicle was also considered. Fine for big open spaces but the signal goes once you've passed a building or even a tree.
A reverse view of torchcam with photographers seated underneath, ready to capture the action
In the end we went for 3G as it seemed to give us what we needed. Network coverage and drop-outs aside, it's not without issues.
When the relay travels to Ireland, for instance, we have to use Irish sims to avoid roaming charges.
So what about the cameras? The only way to get the shots we wanted was to embed the live cameras with the relay so they moved with the torchbearers, telling a story while they gave the viewer a tour of the UK.
To achieve this, one of the vehicles in Locog's convoy has been set up as a mobile broadcast unit. A converted horsebox, It's been fitted with the three cameras and technical equipment that make up BBC torchcam.
The rear camera gives you the classic torchbearer running shot. It needed to deal with all that the UK's roads could throw at it, from speed humps to potholes, so we picked a gyrostabilised camera usually used to cover yacht races.
A "real" cameraman and the electronic one work side-by-side
A second camera on the roof of the vehicle gives great wide views of crowds and scenery and the third, front facing, "convoy mode" camera shows you the road ahead (and, on occasion, a minibus with two bikes strapped the the back of it).
During months of testing, we put the horsebox and the cameras through their paces at the test track used by our colleagues at Top Gear.
At one point members of BBC torch team were doing a simulated relay with planks of wood borrowed from a building site instead of torches.
Some of the kit we're using was still in bubblewrap a month ago and had never been used to broadcast. A week into the relay, we're still tweaking things as we go.
Torchcam is never going to work everywhere. The lack of 3G in some areas of the UK and contention in others make it impossible to achieve total coverage.
The crowds have made the story, but have also made the story a challenge to cover for television and radio.
Getting stuck in the traffic that builds up behind the relay has led to a few hairy moments as camera crews and reporters try to hit their editing deadlines or attempt to get to the next live broadcast position along the route.