A Creative COW Premiere Pro Tutorial
Beaverton, Oregon, USA
©2006 Timothy Kurkoski and Creativecow.net. All rights reserved.
What does the new color depth capability in Premiere Pro 2.0 actually do? How does it differ from its sibling applications? And most importantly, what can it do for you? In this article from Timothy Kurkoski, we're going to explore the enhanced color features in Premiere Pro 2.0 and find out.
Buried in the new feature list for Adobe Premiere Pro 2.0 are the following:
- 10-bit and 16-bit color resolution support
Maintain source integrity with support for 10-bit video and 16-bit PSD files.
- 32-bit internal color processing
Maintain maximum image quality with subtle and dramatic changes to color, contrast, and exposure, free of the banding and artifacts caused by lower bit-depth processing.
Expanded color depth support is a much desired feature for video applications like Premiere Pro, and important to workflows where color range and accuracy is critical. Adobe After Effects and Adobe Photoshop have supported 16-bit color for years and in their most recent releases these two programs now also support 32-bit color and high-dynamic range (HDR) images.
What does the new color depth capability in Premiere Pro 2.0 actually do? How does it differ from its sibling applications? And most importantly, what can it do for you? In this article we're going to explore the enhanced color features in Premiere Pro 2.0 and find out.
We'll start with the simplest of the new features: support for 16-bit RGB Photoshop files. It's very straightforward. Premiere Pro 2.0 can now import Photoshop document files (.PSD) with 16-bit color depth in RGB mode. It's that easy. Note that only the Photoshop format is supported; 16-bit files in other formats like TIFF still will not import. That's a little disappointing, but you can easily convert your TIFF or Targa files using a batch action in Photoshop.
In fact, I've written a simple Photoshop CS2 droplet for you (it may work with earlier versions, but I haven't tested it). Click on the link at the top to download it. Simply drag your files on it, give each file a name when prompted, and they will be saved as a Photoshop file.
Of course, in order to take advantage of the increased color breadth of 16-bit PSD files in Premiere Pro, you need to have the same extra elbow room in your project. That's what 10- and 32-bit support is for.
Previous versions of Premiere Pro have been criticized for lacking native 10-bit color support. You could get 10-bit support by adding a 10-bit capture card from manufacturers like Blackmagic or BlueFish444, but effects native to Premiere Pro 1.0 and 1.5 were still limited to 8-bit processing. Well, not any more.
Five new editing modes, three for HD and two for SD, support Premiere Pro 2.0's native uncompressed 10-bit 4:2:2 YUV codec. An 8-bit version of the codec is also available. These features come as part of a package of built-in support for AJA's Xena HS card. The difference is that you don't need to have a card installed to use them. Where you get your 10-bit footage is up to you.
Exporting to the uncompressed codec (at 10-bit or 8-bit) is also supported, as long as you select the Uncompressed Microsoft AVI option in the Export Settings dialog. The drawback here is that the codec Adobe is using is built in to their new Production Studio applications only, and not available as a DirectShow codec to other applications. Not even Windows Media Player. It's designed for a homogeneous workflow.
There's another interesting option in the Export Settings dialog, in the Keyframe and Rendering pane. The color depth can be set to the Project Setting, forced to 8-bit, or to Maximum. What is this mysterious maximum setting? And what about the keystone in an improved 10-bit workflow, the effects? Keep reading.
32-bit Floating Point and Expanded Color Processing
Where the color processing improvements in Premiere Pro 2.0 really stand out are in the Maximum Bit Depth setting in the Video Rendering options of the project settings, and the matching Maximum rendering option in the export settings.
The Maximum Bit Depth setting tells Premiere Pro that regardless of what project setting you are using, it should render effects at the highest bit depth that the effect supports. This means that 10-bit or even 16-bit footage can be rendered at the best possible quality instead of having to shave off color bits. This can be especially critical during color correction.
How Premiere Pro does this is relatively simple. First it expands the color data in your footage out to fill the expanded 16- or 32-bit range. Then it applies the effect (or effects) doing all of the processing using floating point calculations, which allows it to use the newly created range to preserve color details. Then the color range is contracted back down to the bit depth of the project settings. While some data is inherently lost in this part of the process, the improved accuracy makes up for it.
If you're not familiar with how the range of available colors expands by increasing the color depth, I've created a sample image. The comparisons in this image aren't perfectly accurate, but it does give a relative view of the range of luminance that different color depths give you. There is no 32-bit sample because to make it look different than the 16-bit sample, it would have to be several dozen times larger than the maximum resolution of your monitor.
Now, if you were reading the last few paragraphs carefully, you noticed the catch in how Premiere Pro works in 32-bit. I wrote: at the highest bit depth that the effect supports. That's correct, Watson, not all of the effects in Premiere Pro 2.0 support 32-bit float calculations. In fact, very few do. But they are some of the most important ones. The new Fast Color Corrector and Three-Way Color Corrector will process color in 32-bit float. The Garbage Matte and Chroma Key effects, too. The list isn't long; mostly just the effects that are new to Premiere Pro 2.0 or effects that were significantly revamped, like Track Matte, support 32-bit.
10-bit aficionados shouldn't fret yet, though. There are a good number of effects that process in 16-bit mode, which should look excellent good even if it doesn't have the super-precision of 32-bit float. I wish I could give you a list of what effects work at what bit depth, but alas, I do not have one. My information came straight from a conversation with an Adobe engineer, and all I have to rely on are my memory (bad) and my notes (worse).
There are a couple of details that didn't escape my Swiss cheese brain or my bad handwriting. First is that there are still a number of effects left in the program from the days before Premiere Pro, when all processing was done in RGB. Many effects can now process YUV natively, but there are some that are still RGB only. The difference between RGB and YUV isn't always noticeable, but if you're a color fanatic make sure to always check your work on an external video monitor. Second, synthetic footage in Premiere Pro is 8-bit only. Synthetics are anything that Premiere Pro generates all by itself: color mattes, titles, color bars, etc. That means if you just absolutely need that extra razzle-dazzle on your titles, head over to Photoshop or After Effects.
Speaking of Photoshop and After Effects, how is Premiere Pro's high-color bit processing different from what those applications do? Premiere Pro only uses 16- or 32-bit float processing while it is actively rendering. It crunches the data back down to 8- or 10-bit for display and export. The extra color data is not saved or used to display the image. Contrast this to Photoshop and After Effects, which can not only save to 16- and 32-bit formats (although there are few available yet), they also have controls for controlling how the 32-bit color range is displayed on your 8-bit monitor.
Last but not least, why do you care? Why is expanded color depth important? In one word: accuracy. Expanded color ranges allow video and imaging applications to calculate the differences between black and white with more precision. You'll get less banding in gradients and areas with color transition. The difference between shadows and highlights will be smoother. Color correction can hone in on your desired palette with a finer scale of colors. In general, expanded color depth gives you more control and more potential for realism.
The new color depth support in Premiere Pro 2.0 may not be perfect, but it's a big leap forward. Combined with Photoshop, After Effects, and a good 10-bit capture card, you can open the door to new creative possibilities. These possibilities give you control to achieve your creative vision.
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