Merlin: The special effects
Director, special effects
I’ve been interested in films and effects since I was a child, coupled with an obsession for knowing how things work.
Deconstructing things and making something else from the pieces often led to trouble from my parents.
I’d pull something apart (for that vital cog!) to the point where the item in question was broken beyond repair, generating a corresponding animated reaction from my father.
So to end up in special effects, I suppose was inevitable.
Effects are in essence all about creating an illusion, crafting the image of something happening for real when in reality it’s a manufactured event, like a cave wall collapsing or a building bursting into flames.
Of course the effect you see on the screen has to be controlled and happen without damage to the surroundings, cast or crew so safety is also one of our primary considerations during design and planning.
Working on Merlin was a delight and a privilege.
It was a rollercoaster script full of magic and natural effects (like rain, mist, wind, fire, a net trap etc) - a lot of which could be shot front of camera.
On occasion I had a team of up to six technicians depending on the complexity of the effect.
We’ve had many diverse challenges over the five years of filming from the very simple, such as extinguishing or igniting a burning torch on cue to the more complicated set-up of controlling a boat’s direction and speed around a weed-filled moat.
Earlier effects involved arranging a mattress to move independently around a room, to stop under a falling actor, breaking his fall.
We incorporated a hidden system of wires and pulleys into the set, and the mattress had to change direction too, so some lines needed to be released or extended during its travel.
It was basically a puppet moving on the horizontal plane.
We created a radio-controlled rolling barrel which chased some guards as a diversion, by using an adapted remote control car with a very lightweight barrel fitted to the front on a small universal joint.
Skeleton hands: series three, The Tears of Uther Pendragon - part two
To get these skeleton hands smashing out through stone tomb lids [above], the lids were copied from the originals and made from soft lightweight material which closely resembled stone.
The hands’ movements were operated from beneath.
And of course for the dragons breathing balls of fire in the clip below, we specially constructed pressure vessels to hold propane gas.
The gas was released instantly by a timed valve and ignited, giving precise control over the distance and size of the flame.
From series two, The Last Dragonlord
Whatever the effects, they were always an immense amount of fun to work out, work on and produce.
The snow in this series was one of our biggest setups.
We had the weather to consider when choosing the material as the more economic ‘snow’ was not weather-proof enough to endure a week’s filming in Wales.
The greater challenge, however, was the brief to construct the safe and fast-moving sleigh driven over rough, undulating ground by the lovely Morgana.
Morganna (Katie McGrath) on her sleigh, with Gwaine (Eoin Macken)
We wanted to use the actor (Katie McGrath) and not a stand-in, so for stability we chose to build it on three wheels with the front free steering.
We angled the rear two at 45 degrees to spread the footprint. An advantage of this was a softened, very realistic movement. We avoided using a rail which was both difficult to hide, expensive and also inflexible.
Instead, we pulled the sleigh over 30 metres on a hydraulic winch which, in the end, we had also built as there was not one in existence fast enough for our needs.
The end result was a perfect blend of safety and stable movement matching that of a sleigh at speed.
Colin Gorry is director of Colin Gorry Effects, the company which produces the special effects on Merlin.
It's been announced that the current series of Merlin will be the last. See the official press release on the BBC Media Centre.
Comments made by writers on the BBC TV blog are their own opinions and not necessarily those of the BBC.