Hacker News Reader

If you shoot 120fps with 360° shutter angle you can downsample to 24fps with 144° shutter angle, which is close enough to the traditional 180°. And in any case cinematographers often vary the shutter angle, so viewers are already used to changes. Narrow shutter angle is common in modern action movies.

View on HN

Yes, cinematographers do vary the shutter angle for artistic purposes, but that just confirms the fact that the amount of motion blur present in a film is a deliberate artistic decision rather than a side effect of using an "antiquated" frame rate.

As for downsampling, I believe your math is off. 120 fps at 360° means each frame is exposed at 1/120s. Conforming that to 24 fps gives you the same exposure duration per frame (you're just throwing out 4/5 frames), so you're effectively at a 72° shutter angle - less than half of what's considered "normal".

I only said that 144° effective shutter angle is possible, not that you can achieve it by deleting 4/5 frames (which does give you effective 72° shutter angle). You actually need to delete 3/5 and blend 2/5 (and the 360° shutter angle of the 120fps source needs to be accurate enough that you don't see the join).

Reply on news.ycombinator.com