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Sunday, December 6, 2009

••◊ Online in HD, part 3

The last part of this trilogy has to do with cleaning up the noise and other gunk that is in the video, so it's viewable in 1080p. It's amazing what a difference downscaling makes to the average video. In my particular case, this video was the first thing I had shot with the 5Dm2 and only my second weekend with the camera - thus there was plenty of gunk to clean up. However, that's the reason I took the gear out. I wanted to learn what I was going to mess before messing up on an important project.

The most notable gunk in my laundry list was high ISO video noise. Anyone that owns an SLR knows about the strong direct relationship of high ISO to high chromatic noise. With film we call it "grain" and it often ends up looking like luma noise (i.e. dark dots that appear as noise). In contrast digital cameras produce colorful noise that's extremely ugly and distracting.

So...how to fix it? We need to select a clip. This fire side shot in the evening does quite well as an example. You'll need to click on the photo to see it larger since the aforementioned downscaling hides the noise. After color correction there's all types of red and green noise, especially around the chair and fire.

Step 1. Right click the clip in the Premier timeline and select "Replace with After Effects Composition." This will open After Effect, which has a de-noising effect.

Step 2. When After Effects opens the video from the clip should appear. Go over to the "Noise & Grain" settings in the "Effects and Presets" window and select the "Remove Grain" effect. You should be able to drag and drop this effect onto the video.

Step 3. Since the Remove Grain effect is now applied, you need to manually select how much noise to remove. Too much and the picture becomes blurry. Too little and it's still noisy. To do this open up the effect options in the "Effect Controls" window at the left. I usually find that just using the "Noise Reduction Settings->Noise Reduction" control is easiest. However, the effect allows much more control for the more sophisticated user.

Step 4. This step falls a little into the area on color correction. Individual colors can have their shadows crushed to black using one or more of the color correction effects. I did this on a few scenes and it provided a really nice way to kill off the noise in the darkest areas of the picture.

Step 5. You may also need to restore any Brightness, Contrast, Hue, or Saturation color correction settings you had in Premier. I used the "ProcAmp" effect in Premier and it didn't automatically transfer into After Effects, unlike the "Color Balance" effect which transferred in just fine.

Step 6. Save and exit. That's it. Premier should pick up the After Effects composition and make it nearly impossible to play back without a long, long, long render time. Here's the 1/3rd scale result. Again, the downscaling is hiding any noise improvement, so you'll have to click on the picture to enlarge it and see the result. It should be noticeably better and maybe a little more film-like with the chroma noise obfuscated.

On to the next death defying project.

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