Friday, March 26, 2010
Fake slow motion
This video won Vimeo's Weekend Project in late January 2010. The project was to make "fake slow motion" where it's the actor moving slowly while the shot is rolling at normal speed. To pull off the illusion required some thought and planning.
Seven Factors for success:
1) A tripod
2) Slow but fluid motion of the actor
3) No extraneous background movement
4) Accent special effects
5) Appropriate sound
6) Cuts every three seconds
7) Appropriate story
A stable shot is important. The tripod is the easiest tool to work with in this case. The video was shot at 24 fps. Camera motion is more apparent at lower frame rates. I made sure the wind wouldn't shake the camera. Also be careful to avoid placement near foot traffic. Where possible I turned on the IS feature on my lens.
Slow but Fluid Motion
You need to select comfortable positions and motions. Shots standing still while turning were the easiest to do. Just don't blink. Literally, don't blink! That ruins the illusion. The hardest part of this video was slowing down the opening of the box. It tended to spring on its own. You'll also have to factor where the camera will be for the shot. In this case it was between the arms which did not help.
No Extraneous Background Movement
Indoor scenes are easiest because you can control the environment. For outdoors you have to watch what's behind you. In this video there were people taking dogs out for a stroll. The wind also picked up on occasion. I had to wait for the environment to be right before shooting. Multiple takes are important.
The 7D helped thanks to the shallow depth of field. I opened up the aperture to its widest and framed the shot to limit the distractions. For this video I used a Sigma 18-50 EX Macro F2.8 for the indoor scenes. I used manual focus mode to fix the area in focus. Outdoors was shot mostly with a Canon 70-200 F2.8. I had to mind the minimum distance to get the shots I wanted.
Accent Special Effects
The special effects were made with effects of Sony Vegas 8. Here are the important ones.
Tie in the Wind
I drew a red trapezoid with a dithered fill using MS Paint. Then I deleted the background in Paint.NET. The image was saved as a PNG file with alpha channel. This was imported into its own track in Sony Vegas. I turned on track motion and applied a warp effect to the image. I animated the wave and tweaked it until I got a smooth flutter motion. The track motion was important to keep one end of the tie fixed on the neck. Take note that the real tie was tucked behind the collar under the suit for this shot. To sell the illusion the shirt front has to be bare.
I came to the idea of the fluttering tie while I was thinking of things that would look cool in slow motion. You know how superheroes are shown with capes flying in the wind. Why not a tie? With the animated tie the faked slow motion is complete.
Same idea as above but implemented differently. I had one still photo of a pigeon from a while back. I manually edited components of the still into two three key frames of the bird. Then I put it into the timeline with some overlaps. Sony Vegas interpolated the frames with overlaps which gave me extra effects. I animated the track to give it some movement.
I wasn't too happy with the fake rain. Controlling its motion was hard and it didn't quite work. If I knew Blender I would have animated some particles. Since I didn't I settled with this technique I learned from Youtube.
I cut out the original sound entirely. The ambient noise would not have synced to what the video portrayed.
Cuts every Three Seconds
This is just my style. To keep the story moving without being too hurried I used three seconds between cuts.
Slow motion, real or fake, is easier to believe for two kinds of story plots: heroism and tragedy. That's just my opinion. Okay, so maybe it's also good for comedic effect. But that would be good for maybe one shot.