Film-maker James Routh captured the life-saving work of the Air Ambulance for Medic One.

I usually skip the crime and medical pages of the newspaper; the same goes for my taste in TV. But when North One asked me to shoot the taster tape for Medic One, I was hooked.

The programme follows London's Air Ambulance, an elite team of doctors and paramedics that deals exclusively with major trauma. I was present at some of the most dramatic scenes I have ever witnessed. High on aircraft fuel and adrenaline, I decided that I would love to direct it if it was commissioned.

The BBC commissioned a one-off, for 10.35pm on BBC1. Encouragingly, I was told to make it “my own”, and given total freedom in how to approach it. My exec, Tina Flintoff, only insisted that it should “look like a drama”. On £150,000.

Plus, it would have to be self-shot as there was only one spare seat on the helicopter.

Seeing the air ambulance operate in London - flying around famous landmarks, landing in playing fields and estates - was extraordinary. This film had to capture that. The helicopter can't fly at night, so the team uses rapid response cars instead. This is a crucial time when the team sees people critically wounded from accidents and assaults, including a growing number of stabbings.

My aim in shooting was to combine energy and intimacy with a certain beauty and elegance that defied the budget. High-quality aerial photography was a must, but it was important the shots didn't become grotty when we hit the ground.

I decided to shoot in HDV, and use two Z1 kits - one straightforward, with the usual wide-angle lens adaptor, and the other with a touch of magic, a prime lens adaptor with some old Nikon SLR lenses. Its combination of modern digital technology and 1970s manual hardware suits my tastes.

When you're self-shooting, it's important to work with someone who understands the principles of photography and the equipment needed, while fulfilling the normal producer role. Ed Davies was itching to direct and had a good understanding, but he was also keen to learn more.

The 12-hour night shifts at weekends were punishing but often extraordinary. Ed and I have seen things most people never will, including situations far too traumatic to broadcast. It did force us to examine ourselves, but we both came to realise that like the medics, we were able to detach ourselves from the situations.

The biggest headache in the whole process has been consent, which is perfectly understandable. It never ceases to amaze me how much people are prepared to allow cameras into their lives, but there are limits and we reached them on several occasions.

Medic One is, of course, one of many blue light films out there. But the work done by the Air Ambulance team is extraordinary, and I hope our approach to filming reflects this.

Medic One
Producer: North One Television
TX: May 2009 on BBC1
Producer/camera: Ed Davies
Film editor: Samuel Santana
Executive producer: Tina Flintoff
Filmed, directed by James Routh
Project summary: Medic One follows the work of the Air Ambulance unit as it attends emergencies throughout the capital

James Routh: My tricks of the trade
When self-shooting, try to turn your small camera into a big one. Shoulder mount and pivot from your waist.
Think slow, steady, deliberate.
Try to stay off the motorised zoom.
Make sure your verticals are vertical and your horizons are straight.
Bully your production manager into giving you a proper, fluid head tripod.
An essential but often overlooked piece of equipment is perhaps the most simple - a lens cleaning cloth.
How about a nice, padded backpack to carry the kit? They do exist, you know, despite what your production company says.