I'm sure most of us are familiar with the scene in Stanley Kubrick's 2001: A Space Odyssey where Dave is flying through the stargate, but have you ever wondered how the filmmakers achieved that trippy effect? Well, today you can obtain this using animation or editing software, but the mechanical special effects technique is called "slit scan", and John P. Hess from Filmmaker IQ walks us through how to achieve this effect digitally with After Effects, as well as physically with a camera, a mechanized slider, and LEGOs.

If you're not familiar with the stargate scene from 2001: A Space Odyssey, here's a video to demonstrate what the slit scan technique does:

Video is no longer available: youtu.be/YbLRzabppus?t=45s

Slit scan photography, in one form or another, has been around since the 1800s, used mostly for panoramic images (for determining winners at racetracks.) The technique is achieved by putting a moveable slide with a slit cut into it between the subject and the photographic plane. The medium used is exposed as the slide moves across one side to the other.

This technique used in Kubrick's 2001 was developed by the film's Visual Effects Supervisor Douglas Trumbull. Even though Trumbull attributes the technique's origin to John Whitney, Trumbull was the one who had the idea to put the slit outside the camera.

Here's Trumbull talking about the slit scan technique he used in 2001:

So, do you want to learn how to make your own slit scan sequence? Filmmaker IQ offers a great tutorial on building your own rig, so gather your LEGOs and check out the video below:

Video is no longer available: vimeo.com/71702374

If you want to make a slit scan sequence without all the hassle of constructing a setup, here's a tutorial on how to make a digital one using After Effects.

Video is no longer available: vimeo.com/71702373

What do you think? Have you ever filmed a slit scan sequence mechanically before? What about digitally? Let us know in the comments.

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