Grading with Color Wheels

Recently fellow editor Shane Ross and I were discussing the relative merits of grading in Avid Media Composer versus Apple’s FCP or Color, as well as using the Colorista plug-in. Our conversation got down to how each treated the image when you used the color wheels. After I did a quick test, it was obvious that FCP and Avid don’t process the image in quite the same way, even when you push what appears to be the equivalent control in the same direction. So I decided to dig a bit deeper.

The so-called “color wheels” (also called hue offset controls) are separate color balance controls for the shadow, midrange and highlight portions of the image. When you want to effect a change, such as make an image less red, you push the appropriate control in the opposite direction of red-yellow – towards the blue-cyan segment of the control. In addition to low/mid/high ranges, some applications also add an overall “master” balance control for the entire image.

The concept of these tools grew out of early “video shading” controls in studio cameras and color correction systems like DaVinci. To my knowledge, the first actual use of software color wheels originally appeared in Avid Symphony a decade ago.

Since the controls work within three distinct ranges of the image, a critical element is where that crossover occurs between low-to-mid and mid-to-high. Not only where, but also how gradual the transition. Some apps and plug-ins give you control over this and some don’t. If so, look for either a threshold control or a luma ranges control to adjust the transition point and the softness of that transition.

Some points to remember:

a) Not all color wheel adjustments give you the same degree of saturation. If I push the mids to blue, some apps let me really blow out the image with blue saturation, while others only slightly tint the image.

b) A proper color balance control should increase the saturation of the color component you add (or shift to), while reducing the saturation of the complementary colors. This should be evident on a waveform monitor’s RGB parade display. In fact, some only increased blue, while others also appropriately reduce red and green color components.

c) Some have a very tight default threshold at the low/mid/high crossover points and others are very gradual. The softer the threshold or transition between ranges, the more the color balance change looks like a tint or wash over the whole image. The tighter the default transition, the more likely you will see contouring artifacts at the edge of the transition.

The following are the results of my casual testing. I took the same image I’ve used for other color grading articles. This started out as a flat RED One image, which I’ve cropped to HD and increased contrast and saturation.

That’s the starting point for these tests. I wanted to use an image that looked like what you are apt to receive, rather than a flatter image, which would actually be preferable for grading. In each of these applications I have simply increased the blue balance in the mid-range control, without adjusted any thresholds or other controls. In most cases, I’ve pushed the control as far as it would go – either to the edge of its range – or to the point where I started to see some color artifacts. Most importantly, I was NOT going for the best-graded image. Instead, I’m trying to demonstrate how seemingly similar tools can actually give you wildly different results. A tool will an extreme range can often make grading more difficult, because it’s harder to achieve finesse.

Click on any of these image for a larger (and often expanded) view. At the bottom, I’ve included a series of exported images from each of these applications.

Apple Aperture

Aperture neutral

Aperture adjusted

Aperture is here only as a frame-of-reference. It offers similar color controls to some grading applications and presumably would have the most graceful processing of the image.

Avid Media Composer

Avid neutral

Avid adjusted

Avid Media Composer does a nice job of staying within the mid-range. It also tends to reduce red and blue while increasing blue.

Apple Color

Apple Color neutral

Apple Color adjusted

The interesting thing about Color is that the app not only made the image blue, but it also seemed to darken it, compared with the other grading solutions. You can see this below in the exported image. The Color image was round-tripped through FCP.

Apple Final Cut Pro (3-way color correction filter)

Apple FCP 3-way neutral

Apple FCP 3-way adjusted

Apple FCP’s 3-way had the most extreme range, but it seemed to just increase blue without reducing the other colors. You’ll see that a color segment can be completely blown out by this control.

Red Giant Magic Bullet Colorista color correction filter (Apple FCP host)

Colorista adjusted

Red Giant’s Colorista grading filter is the one that many editors gravitate to when the built-in controls aren’t enough. As you see, it offers more graceful color control in FCP than the standard 3-way. Unfortunately, it’s also one of the few FCP plug-ins I use that is extremely picky about versions. If you move a sequence between systems and have a mismatch of Colorista filters installed, it can completely crash FCP or Motion. I find that it’s much better behaved in After Effects. There you also get additional tools, such as a collection of Colorista presets.

Red Giant Magic Bullet Looks

Looks neutral

Looks 3-way adjusted

Looks lift-gamma-gain adjusted

Magic Bullet Looks is another powerful third party plug-in that lets you chain a series of internal filter together – all within its own interface. Looks offers several controls for color correction, including both a 3-way and a lift-gamma-gain control. The two sets of controls appear similar, but don’t work the same way. The lift-gamma-gain control works like Colorista, while the 3-way works more like Adobe’s built-in color correction. You’ll notice on the 3-way that the range isn’t as great and the default threshold is very tight (but adjustable). Note the contouring on the model’s shoulder blades.

Adobe Premiere Pro (3-way color correction filter)

Adobe Premiere Pro 3-way neutral

Adobe Premiere Pro 3-way adjusted

This is my least favorite filter in the batch. Like the Looks 3-way, the level of blue that was increased is pretty minor and the threshold is also very tight (but also adjustable). As one would expect with a tight threshold, there is also visible contouring at the bottom of her back in this image.

Synthetic Aperture Color Finesse color correction filter (Adobe After Effects host)

SA Color Finesse neutral

SA Color Finesse adjusted

Last in this set of comparisons is Synthetic Aperture’s Color Finesse 2 plug-in that ships with Adobe After Effects. Color Finesse offers a toolset that is very similar to Avid Symphony and has been included with After Effects for years. In addition to all the standard color grading models, Color Finesse also offers more advanced modes, like CMYK grading. If you have a two-monitor configuration, the Color Finesse UI displays a full-screen image on one of the monitors.

In my opinion, Synthetic Aperture Color Finesse produced the most pleasing results out of all of these video images. A version of Color Finesse is also available as a standalone grading application, which uses a similar workflow to Apple Color. In any case, it’s right inside Adobe After Effects, though many editors aren’t even aware of the power they already own if they have the CS3 or CS4 bundle!

Exported images

Starting image

Apple Aperture

Avid Media Composer

Apple Color

Apple Final Cut Pro (3-way)

Red Giant Colorista (FCP)

Magic Bullet Looks (3-way)

Magic Bullet Looks (Lift-Gamma-Gain)

Adobe Premiere Pro (3-way)

Synthetic Aperture Color Finesse

©2010 Oliver Peters

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