In Depth: Time Effects - Time Displacement aka Slit-Scan, with Examples

By Michele Yamazaki on Jan 17, 2013 at 07:42 PM

Introduction

A few months ago, Eddy Bergman posted a tutorial Slit Scan or Time Displacement Effect Tutorial for his site After Effects Tutorials, on our After Effects Portal Facebook group. He used the Muse video, Unintended, as an example, which utilizes the slit-scan Photography technique. Now, I'm a HUGE fan of Muse and I had never seen this video. What can I say? It's trippy! The slit-scan effect is used throughout the video and applied to slow-mo footage. 

Muse - Unintended

Slit-scan Photography has been around for years, but unless you've done it, you may not know exactly what it is. There's a really well known sequence in Stanley Kubrick's 2001: A Space Oddyssey that uses the slit-scan technique, and you've probably seen it but may have not known what it was called. (By the way, you can see the original images used in the 2001 slit scan sequence here.)

So, what is slit-scan photography? According to Wikipedia, using the traditional methods:

The slit-scan photography technique is a photographic and cinematographic process where a moveable slide, into which a slit has been cut, is inserted between the camera and the subject to be photographed.

With modern software, you're basically playing one portion of the frame faster than another portion so that footage and elements in the video are stretched, squeezed and twisted, based on movement. This effect really gives footage a strange, surreal look, which works well when filmmakers are trying to show another dimension, time travel, or an LSD trip.

More Examples

So that you get a better feel about what can be done with this technique, here are a few samples.

Doctor Who title sequence (1973-74)

Total Recall Title Sequence 

We're talking about the original from 1990, by Title Designer Wayne Fitzgerald, also known for Bonnie and Clyde, Rosemary's Baby, Guess Who's Coming to Dinner, Footloose, Tootsie, Splash, Ghost and so many more.

Day 244 / Slitscan Experimentation

Day 244 / Slitscan Experimentation from Charlie Visnic on Vimeo.

Slit-Scan Movie Maker Samples

This piece by Trevor Alyn was created using the Slit-Scan Movie Maker, an app which he created, available in the Mac App Store.

How to Make Your Own Slit-scan Effect in After Effects

Watch the video below to see a quick comparison of similar settings in After Effects Time Displacement, Boris Continuum Complete BCC Time Displacement and GenArts Sapphire S_TimeDisplace. I will be referring to these examples in the following descriptions.

After Effects Time Displacement Filter

Although it looks cool and complex, Time Displacement is a very simple effect to apply. It will definitely take some finessing. The effect consists of two parts: the footage layer and a gradient, which feeds luminance levels to the time displacement. Here's how you do it (and I'll assume that you know the basics of After Effects... you know, things like precomping, basic effects, etc.).

1. Apply the Time Displacement effect to your footage that you want to distort. After Effects uses the layer your footage layer in its original form. If you applied any effects (other than Time Displacement), masks or transformations, you must precompose those effects, masks, etc. using the Move All Attributes checkbox in the precomp dialog box. Then apply Time Displacement.
2. You will notice it looking all funky and this is because it's using the layer of footage as the Time Displacement Layer. 
3. Create a New Solid layer that is comp sized. Apply a grayscale gradient or ramp to the layer. Precomp the gradient, moving all attributes to the precomp.
   
   A note on the gradient. The Adobe Help docs explain it well enough:
   

   In grayscale images, the luminance value range extends from 0 to 255, and it’s converted to a scale ranging from -1 to 1. A luminance value of 0 produces maximum backward displacement, meaning that pixels at the current time are replaced by pixels from a previous time. A luminance value of 255 produces maximum positive displacement, meaning that pixels at the current time are replaced by pixels at a future time. A luminance value of 128 produces no displacement. For other values in grayscale displacement maps, you can calculate the displacement amount, in seconds, using the following equation:
   
   Displacement amount in seconds = maximum_displacement_time * (2 * (luminance_value – 128) / 256)

4. In the Time Displacement effect, choose the gradient layer as your Time Displacement layer. You can place it below your footage and turn off the visibility for the gradient layer. 

5. When you preview, you should now see the effect. This is where you'll want to tweak the values for Max Displacement Time [sec] and Time Resolution [fps]. You will also likely want to adjust your gradient.

Tip: Notice how the effect does not look as good in the video footage in the beginning of this section, but looks stellar on the text sample with the word "Toolfarm". The clean edges were achieved by cranking up Time Resolution to 150fps. The drawback to upping the value of Time Resolution is that there is a huge render hit. 

Boris Continuum Complete BCC Time Displacement

Toolfarm Price: $995 Download Free Trial

Host support:

• Adobe After Effects
• Adobe Premiere Pro
• Apple Final Cut Pro
• Apple Motion
• Avid Media Composer
• Avid NewsCutter
• Avid Symphony
• Avid DS
• Sony Vegas Pro

The BCC Time Displacement works a lot like the AE plug-in but has several more bells and whistles and just gives a lot nicer of an effect on footage, in my opinion.

Why is it better than the one that ships with AE?

1. The stripey, aliased look which occurs when something in the shot  is moving fast is smoothed by checking the Frame Blending box. 
   
   If you haven't seen the sample above in this section, see the footage examples of the AE Time Displacement filter vs. BCC Time Displacement. I used similar settings but used the Frame Blending option on BCC Time Displacement. The Difference is clear. BCC Time Displacement is the clear winner when it comes to displacing footage. The Frame Blending feature makes the distortions much less choppy. Frame blending did not however help with the text example.
2. Presets, some of which are animated. 
3. The Displacement Channel pulldown menu allows for channels other than the luminance channel. The choices are Red, Green, Blue, Luma,White, Gray, and Black.

 Download a PDF on the BCC Time Displacement Filter

GenArts Sapphire S_TimeDisplace

Toolfarm Price: $1,699. Download Free Trial

Hosts: 

• Adobe After Effects
• Adobe Premiere Pro
• Autodesk Combustion
• Autodesk Smoke for Mac
• Apple Final Cut Pro, FCP X and Motion
• Autodesk Flame, Inferno, Flint & Smoke
• Autodesk Flare
• Avid DS Nitris or DS/Symphony
• Avid Media Composer/Symphony/Xpress/Newscutter
• OFX for Nuke, Fusion, Sony Vegas, or SCRATCH

The third plug-in I'm covering is in the Sapphire package, and although GenArts normally hits them out of the park, I do not love this filter. It doesn't give as smooth of effect with footage as BCC Time Displacement or with text like the AE Time Displacement does. A frame blending option is needed in a big way. There's just a single preset and it's the default setting. It worked about the same as the AE Time Displacement filter does on footage, but didn't fare as well on text. 

I could live with all of that but the killer was that it caused AE to crash on render, 6 times in a row. Sapphire is normally the Clydesdale of plug-ins so it surprises me that I could not get it to render. I ended up removing it from my sample above because I just couldn't get it output.

Tips for Best Results and Experimenting

1. Shoot your video at as high of frame rate as possible. This will allow you to use slow-mo'd footage, which looks really cool with Time Displacement. 
2. Use a tripod. Handheld footage with a lot of movement does not Time Displace well
3. Try the effect on 3D Solid Layer with the Y rotation keyframed for some cool twisting box effects.
4. If you're not getting the effect that you like, experiment with moving the gradient, adjusting luminance values and keyframing the position of the gradient points. 
5. Search YouTube for more Slit Scan and Time Displacement examples. There are some really neat videos out there. 
6. Try combining the effect with other time plug-ins. You may need to precompose each time you apply the effect.

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