The commercial "Guinness Surfer" (Computer Film Company, UK) directed by Jonathan Glazer and produced for TV, combines real shots and computer graphics in evocative black & white pictures. It shows a group of men surfing. Suddenly a gigantic wave rises up and white horses emerge from the foam. Men and horses move forward on, under and in the wave.

For several long seconds the camera lingers on a man's face. He is waiting. At last we cut to hand-held footage following the man and his three companions, all carrying surfboards. They hurl themselves into a heaving ocean. The ultimate wave has arrived. It starts to roll and we see that the men are not alone. The spirit of the wave is physically embodied in enormous white horses which are charging through the water with them. Above, below and inside the wave men and horses surge thrillingly forward.

This astonishing visual effect was created by The Computer Film Company for the latest Guinness television commercial, "Surfer", which first aired on 17th March 1999. Acclaimed director Jonathan Glazer has collaborated with CFC before, initially with the Nike "Parklife" commercial. The company also produced some alarmingly realistic effects for his controversial music video for U.N.K.L.E., "Rabbit in Your Head lights." "It was the painterly quality that CFC's designers brought to one of the U.N.K.L.E. shots that gave me the confidence I needed that they could handle this work," recalls Glazer. "I wanted some thing that was mythological and yet utterly real. Working with such contrasting elements, one liquid, one muscular and solid, they produced of the most extraordinary compositing work I've seen."

Rumour has it that the brief for the commercical was daunting enough to frighten off some other effects houses but, says Senior Visual Effects De signer Paddy Eason, "The scary jobs are the ones that make all this worth doing."

A number of ways of achieving the creative team's vision were considered, including doing it all as CG, or using real waves but CG horses, both of which would haven given the team greater control but, as Eason notes, "We are very aware that the kind of happy accidents you get in the real world, the natural movements of waves and horses, will always give you a better shot. So our final choice was to use real waves and horses, where necessary adding CG water and the odd CG horses leg." Dominic Parker, head of 3D, adds: "We wanted to find a way of con veying the chaotic and violent dynamic of the film using CG elements to fill in the gaps from the shots-under water hooves, bubbles, surf, spray, and spume."

The film celebrates the pleasures in store for those prepared to wait, though waiting was not a luxury available to the team at CFC. "Although we'd obviously done some planning, there's only so much you can do in advance with this sort of material," says Rachael Penfold, Senior Visual Effects Producer at CFC, "The surfers were shot in Hawaii and we'd given the crew as much information as possible beforehand about what we hoped for, but we really had no idea what we would get-the size of the waves, the weather, so much was beyond our control. Once we had a rough cut, we used it to decide what we needed from the 3 day studio shoot of horses, tip-tanks and spray. We shot these ele ments at very high speed using a Photosonics camera, so we had thousands of feet of film which we used to create a library of images which the team could draw on."

The footage was shot, composited and had FX added in colour before being transformed into black and white, so that the final look is not stark but has a range of mercurial greys, helping convey the chaos surrounding the surfers.

The project was headed at CFC by Paddy Eason and Dan Glass, though the finished film drew on skills from right across CFC's areas of FX expertise. "The composting was done by Paddy, Adrian de Wet and myself," explains Glass, "We used Cineon running on Silicon Graphics machines. Keylight (keying software, developed in house but now commercially available) was invaluable during this process." Silicon Graphics also supported Matador, which Gavin Toomey and Alex Payman used for the paint work. Dominic Parker and Richard Clarke worked on the 3D elements using Houdini, Maya & Renderman, and the final conform and grade was completed on Domino by Tom Debenham.