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It wasn't until I was shopping for an LED TV that I really understood a lot of the important details in how a sequence of images can be made to look like the im

by aimor 4y ago

It wasn't until I was shopping for an LED TV that I really understood a lot of the important details in how a sequence of images can be made to look like the images are in motion. The biggest revelation was the difference between showing a still image for just a moment vs holding that still image on screen for a long time. Illuminating the screen pixel-by-pixel with a short duty factor gave CRTs sharp crisp motion compared to LED and LCD screens. The UFO tests really drove the point home (along with a lot of other visual phenomena). https://www.testufo.com/blackframes https://www.testufo.com/blackframes What got me hung up for so long was that so much of the conversation has been about frame rates and shutter speeds, when it's really a different (but related) effect. I've been wanting to play around with high framerate video with frames combined to mimic slower shutter speeds. That is, 120 Hz open shutter video blurred with a 4-frame sliding window to look like it was shot at 30 fps. Or other such tricks. I thought high-end cameras might do such things automatically but it seems like they don't and I want to figure out why not. (does it look bad?) https://kevinlisota.photography/2020/04/understanding-video-frame-rate-and-shutter-speed/ https://kevinlisota.photography/2020/04/understanding-video-... https://www.cnet.com/tech/home-entertainment/tv-motion-blur-explained-and-why-all-the-4k-tv-solutions-fall-short/ https://www.cnet.com/tech/home-entertainment/tv-motion-blur-...

uxp100 4y ago
That would not look like 30 fps necessarily. The keyword you want to learn about is “Shutter Angle”
- aimor 4y ago
  That's right, my example was off because film is 'usually' shot 180 degrees. So 30 FPS has an effective shutter of 1/60", and 120Hz open shutter needs a 2-frame sliding window to match that look. Or use a 3-frame window for 1/40", a more blurry film (1/48") look. There's power in being able to make that choice when editing. What I'm not sure about is how similar merging two images together will be compared to doing it natively with the camera. I'm guessing it will look slightly different, but I'll find out when I try it.

by aimor 4y ago

uxp100 4y ago

That would not look like 30 fps necessarily. The keyword you want to learn about is “Shutter Angle”

aimor 4y ago
That's right, my example was off because film is 'usually' shot 180 degrees. So 30 FPS has an effective shutter of 1/60", and 120Hz open shutter needs a 2-frame sliding window to match that look. Or use a 3-frame window for 1/40", a more blurry film (1/48") look. There's power in being able to make that choice when editing. What I'm not sure about is how similar merging two images together will be compared to doing it natively with the camera. I'm guessing it will look slightly different, but I'll find out when I try it.