Ravage was one of the trickiest robots to pull off.

Farrar also touts the higher degree of acting. Jetfire, the old SR70, is the best example. They added more pieces to the face as they went along to increase articulation and emotion and line delivery. "He has a sneer at one point, so we had to redesign the face and the eye area so he could wince," Farrar explains. "That's the new, big challenge: to show more emotion, which was our main goal. Cars are the hardest things to light and each one has to reflect the environment. And there were a lot of environments. Ravage, the stainless steel cat, was tricky. He's a heated blue, darkish steel. You spend a lot of time fishing around for what the look is. You light it, you look at it and you keep add some scorching, you keep fiddling with things until you finally have something that looks good."

Benza says they did a full series of tests for Jetfire. "It was hard to find a guy who had a grizzled, veteran feel to him but was also decrepit or broken down," according to Benza. "Through a series of reference we found [the right mix] of acting and voice. We went down the path of doing a compilation and it ends up being what you see in the film. He's a war veteran that's tired of fighting for the wrong side. 'Too old for this shit' is how we described it and that line actually made it into the movie."

Benza offers that they greatly improved the fight choreography. "In the first film, the fights were much shorter and less choreographed. We put a lot of time and effort in fleshing those out. We utilized a lot of martial arts influences and spent about two months doing previs for forest fight sequence and did a full three-minute animatic (in Maya) before the plates were shot for that sequence.

"The only requirement from Michael was he wanted to see hooks coming out of Optimus' hands and rip the helicopter robot's face in two. That was the one idea that we wrapped the entire fight around. The fight is a couple of minutes long and a longer version of the fight sequence appears in the IMAX version.

Interestingly, Benza's personal contribution was pretty unusual. "I did a couple of editorial passes on the two fight scenes: the forest fight and the fight between Bumblebee and Rampage. Since we had done previs, I was on the New Mexico shoot, where we did background plates for that scene and we had another representative that supervised the shoot of the Bumblebee fight, and Michael thought it would be a good idea to basically dump all of that footage in my lap to take a first pass at editing those fight sequences together. So I went through all the footage and found the best-looking plates for the previs that we had designed. Not everything was designed to match the previs, but I was able to come up with a proposal for him about how the sequences should be put together and gave that to the editors, who then made adjustments and refinements and condensed it for what they wanted with Michael. It was a pretty neat experience."

Meanwhile, shooting the forest fight and climactic battle in IMAX was great fun but a concern. "Devastator was going to fill the frame along with Digimatte backgrounds, which is all res'd up from stills, so it was all us in that frame, which is eight times more film frame than 35mm anamorphic frame, eight times more disk space and eight times longer to render," Farrar says. "It took 72 hours per frame to render Devastator. We tried a little bit of everything for the forest fight. It's still an action sequence but the hard part was shooting thematically. We know the IMAX people tell you to slow the camera down and lock it off. Well, that's not how Michael shoots. We have pause moments, where you see the characters slow down, but then we have high speed and go back and forth that way. It's always experimentation and I hope it's successful. It is a fight after all.