SMALLGANTICS™
"Simulating miniature DOF on full-scale moving footage"

by
Jim Clark

08.06.2007


Earlier this year I was introduced to the captivating aerial photography of Olivo Barbieri via a web link sent by a long-time friend and professional photographer. I was immediately fascinated with the look and wondered how it might be achieved in motion. I took it upon myself to discover a process that would accurately let me recreate the same images I had seen as a child whenever we flew: the tiny streets, animals, buildings, trees and vehicles. I had seen the world from the air as a gigantic miniature and now Barbieri's images inspired me want to create my own miniature worlds, but I needed to figure out how to do it with moving footage. And I wanted to do it accurately, because Barbieri's tilt-shift technique was only a simulation of true DOF...


Early still image test with eight planes of DOF.

To begin, I created a simple fake with a sequence of stacked masks in Photoshop then blurred each region independently to create the miniature DOF look. The images had potential, but lacked the realism that true macro photography offers. It soon became clear that even the stunning images that Barbieri shot were not using true depth of field, but rather, they were achieved through shift-tilt lenses. Unlike the narrow depth of field made possible with telephoto and macro lenses, the shift-tilt technique does not create true DOF. Instead it positions the lens off angle to the back plane of the camera, blurring the top and bottom, or left and right side of the image. Accurate depth of field blur is created by the distance from the lens to the subject. Shift-tilt merely fools the eye into seeing a full-scale landscape as miniature through what appears to be macro DOF, but certain objects in the frame betray this illusion. For example, a telephone pole extending vertically from the bottom to the top of the frame, with tilt-shift, would appear soft at the bottom, sharp focus in the middle and return to soft focus at the top. With real depth of field, because the entire pole is the same distance from the lens, hypothetically speaking, the depth of focus should remain constant from top to bottom.


Early still image test with fake DOF.

Shift-tilt is a clever approach, but I wanted to find a way to capture the subtle complexities of true DOF and completely fool the eye. Moving imagery, especially helicopter footage, proved an insurmountable barrier with the shift-tilt lens, because it's impossible to practically create an accurate DOF effect at that scale without massive lenses in the 1000mm+ range.


Still image test with eight planes of DOF.

I coined the simulated full-scale DOF process 'Smallgantics' and after a lot of experimentation and many failed approaches, I was ready to apply the technique to the right project. Soon thereafter I was offered the great opportunity to oversee the creation of eight Smallgantics sequences for the Thom Yorke video "Harrowdown Hill", directed by Bent Image Lab co-owner/director Chel White. Visual effects artist Jalal Jemison was brought aboard to help me execute and guide a team of artists who executed each shot by hand.


Early still image test with eight planes of DOF.

Bent was awarded the project and our team had only 3 weeks to deliver the finished video. Along with the eight Smallgantics shots we tackled, the  video also contained stock footage treated with a glass pass technique developed by White, eagle animation by David Russo, live underwater footage of Yorke shot in LA at 150fps and beautiful motion controlled time-lapse footage by long time Bent DP Mark Eifert. All in all, the Bent team delivered more than 4 minutes of original and treated stock footage in under a month.


Early still image test with ten planes of DOF.

To better understand the Smallgantic challenge, our team had to first consider the footage that needed treatment. We soon discovered that every shot would require a unique approach, depending on foreground elements, camera angles and scene complexity. We also discovered that moving footage would be much harder to treat than we'd anticipated. In the end, all eight Smallgantic shots were accomplished by a team of six full time compositors over a 3 week period. To complicate our task, we chose to execute the video in full 1080 HD resolution for future delivery.


Early still image test with five planes of DOF

The greatest challenge we faced for Harrowdown Hill was creating artificial depth of field planes that occur in the real world, which would give Chel and our team total DOF control. Basically, we needed to have the ability to pull focus through each shot and/or set the front and back focus at will. To say the least, it was a great challenge and required the skilled hands of the talented Bent team to pull off such a monumental feat in such a short time.


Early still image test with two planes of DOF

 


Final frame from Harrowdown Hill


Final frame from Harrowdown Hill


Final frame from Harrowdown Hill


Final frame from Harrowdown Hill


Final frame from Harrowdown Hill


Web Links:
Thom Yorke music video - "Harrowdown Hill": LINK
Bent Image Lab website: LINK
Chel White website: LINK
Jim Clark design blog: LINK
Jim Clark website: LINK
Jim Clark IMDB: LINK