
I’m happy to see that Christopher Nolan’s Inception is coming out on IMAX next month. Anyone who has seen The Dark Knight on IMAX should know what Nolan and Pfister are capable of.
Still, one question remains, will it be a 35mm conversion (like 99% of commercial IMAX releases) or did they actually shoot some scenes using IMAX cameras (like they did with The Dark Knight). The answer lies somewhere in between.
Unfortunately, no IMAX cameras were used during the filming of Inception. Instead, key scenes were shot in 65mm. What is 65mm? Allow me to explain.
Most movies are shot on standard 35mm film. Sometimes they are blown up in post production to fit on IMAX screens, like with Harry Potter or Transformers.
65mm is a large format film, which offers a higher resolution than standard 35mm. Each frame of a 65mm print has a height of 5 perforations. But when you take the same film and run it through a camera horizontally, so that each frame has a width of 15 perforations, you get IMAX, the highest resolution of any film. This is how all those Dark Knight scenes were filmed.
So, no, Inception did not shoot any scenes with 15-perf IMAX, but they did shoot with 5-perf 65mm, the next best thing. The diagram below shows the relative sizes of 35mm, 65mm, and IMAX.

Check out this interview for more info on Inception [Collider]