Bryant Frazer interviews Siegfried Foessel, Fraunhofer IIS
As head of the Moving Picture Technologies department at the Fraunhofer Institute for Integrated Circuits (IIS) — home of the MP3 and H.264, among other crucial digital content creation technologies — you can imagine Siegfried Foessel has been taking a very close look at techniques for capturing and displaying high-frame-rate (HFR) movies. With discussions still very much open about the benefits of 48 fps versus 60 fps, as well as the issues of converting HFR productions for exhibition at lower frame rates, there are still plenty of questions about best practices for exploiting the increased temporal resolution of high-frame-rate capture. As The Hobbit begins screening for critics and audiences worldwide, we asked Foessel to fill us in on what he and his colleagues have learned about HFR acquisition — and why shooting at 120 fps might be the best plan for anyone looking to maximize flexibility for HFR post-production and delivery.
StudioDaily: Tell us about your work on high-frame-rate cinema.
Siegfried Foessel: We have been working on this for more than 20 months. We started our investigations with equipment from ARRI [two Alexa cameras running at 120fps] and Stereotec [a mirror stereo rig and an on-set stereographer] and a test shoot in a boxing club at 120 fps.
Why did you select that shooting speed?
We wanted to check the differences in visual perception between 24, 30, and 60 fps. From 120 fps, we could easily downconvert it to lower frame rates. If you shoot at 120 fps, you can create a virtual 24, 30, or 60 fps rate with different exposure times and different shutter angles by combining two, three, or four images.
What did you learn?
We saw that, especially for fast movement, it’s quite good to have the higher frame rate. You have less blur and fewer motion artifacts, and it gives you a more realistic impression. On the other hand, we did some tests regarding the bit rate and, especially at higher frame rates, we saw that it makes no difference whether you have 250 Mbps or 500 Mbps. The movement is so fast that you cannot follow it directly. [more…]