Image © Vincent Laforet
Vincent Laforet has a posted stunning new video made during the brief 72 hours for which he managed to get his hands on a pre-release Canon 5D Mark II.
You’ll immediately notice two things about it. I mean, once you get past the Moby soundtrack and helicopter shots:
- It’s gorgeous and
- It looks like video.
There are two reasons for the latter. The first, as previously discussed, is that it’s shot and shown at 30 fps.
But even more responsible for the video-like appearance of some shots is the shutter interval. Film usually has a shutter speed of 1/2 the frame duration, e.g. 1/48 second shutter speed for 24 fps. Video, unencumbered by a physical shutter, often has a shutter speed equal to the frame rate. The most video-like sections of Vincent’s short are those with 1/30th shutter speeds.
This issue plagues many 24 fps HD examples as well. Even at 24p, a “360 degree shutter” results in too-smooth motion with a video-like appearance. You may have seen this in some Hollywood movies shot with 24p HD cameras. It’s not the dynamic range or resolution that blows it for digital movies—it’s a simple choice to use a shutter speed impossible on a film camera.
I’m not trying to critique Vincent’s beautiful piece at all, just hoping to preemptively answer the question of why some 30p samples can indeed look filmic, and some don’t.
I’m also seizing this opportunity to discuss the 360 degree shutter issue, as it’s one that needs airing out. Sure, it may be a creative choice for a filmmaker to use a greater-than-180-degree shutter, but when my mom sees the trailer for Collateral and asks me why it looks like video, we’re talking about a choice that sets back the progress of digital cinema. If you want your 24p HD to look like film, the film we know and love, stick to a 1/48 second shutter speed or faster.
It gets right back to good old less is more—not only is 24p a minimal frame rate, it turns out that a big part of the signature film look is that you only see half the motion in each of those 24 frames per second.
In other words, 24p is only one part of what the filmmaker needs from an HD-equipped DSLR—another, equally important component is manual control, specifically the ability to enforce a 180 degree (1/48 at 24p) shutter speed.