Last week I worked some visual effects shots for a Latin music video of two Sony artists Dyland & Lenny. One of the locations was a greenhouse-like structure with an open door. Through the door was a bluescreen which was supposed to be replaced with a beautiful tropical beach vista. Sounds simple, right? Not even close!

There were a few key factors that made the bluescreen keying a huge challenge.

1. The video was shot on Super16mm (on ultra fast film) and transferred to HD. The result was extremely grainy footage. Sometimes individual grains in dark areas were larger than image details (like hair strands)  in bright areas!
2. The blue panel serving as the bluescreen was not very evenly lit and in some shots, it didn’t cover the entire area to be keyed. Still, important objects, such as the artist’s head, were in this area.
3. The actual set was an exterior, casting a slight blue tint over everything in the scene and gradually varying the lighting from setup to setup.
4. The artist was wearing blue jeans. I swear.

The approach I took with most of the shots was to manually mask out the rectangular area of the door, tracking all the camera movement and perspective shifts…

Then key and finesse the artist’s body with any and all methods available. This included segmenting off different areas of detail and chromakeying them with individual settings, using luma mattes and animated masks with “inner/outer” key. In a few cases, full-out rotoscoping was required.

As mentioned, the camera moved very freely – panning, tilting and dollying. The background image had to be tracked with whatever reference was available in the rest of the image. I used only 2D tracking but actually ended up figuring out a cool technique for adjusting After Effects’ perspective corner pin tracking results which I’m sure will come extremely handy in the future.

Lastly, because of the 16mm large grain format and low shutter speed, the image had a very specific look which had to be emulated on the artificial background to make it look natural. With a combination of color correction, blurring and film grain, I got a pretty close match. Ironically, the grain was the most processor-demanding effect and increased the rendering time exponentially.

Overall, it’s not the most impressive keying job, but considering the limitations, I’m pretty proud of the results. And the music video is very nice. Look for it… um, wherever it is that Spanish music videos come out. MTV Latino?…

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Posted in Company Journal by Alan 2 Comments