Why does keyframing color correction make dot travel in an arc?

riredale wrote on 9/9/2004, 1:46 PM
I tried using keyframing yesterday on a shot where I walked from indoor lighting to outdoor lighting. The camera was set for incandescent, and when I went outdoors the lighting turned very blue.

I opened the color corrector, and set a keyframe for the indoors and a second, blue-adjusted keyframe for the time where I was outdoors. The keyframes were set to "smooth."

The color correction works fine, but in the transition from the first to the second keyframe I note that the color wheel "dot" moves in a counter-clockwise circular arc, rather than just in a straight line from the first setting to the second. Why?


jeremyk wrote on 12/4/2004, 4:23 PM
I finally figured this out today when I was trying to use keyframes to turn a still gradually from a sunset look (reddish) to a nighttime look (blueish). Rather than going through a sort of neutral magenta phase on its way, it goes through a really bright magenta phase.

Even though the correction dots are plotted on a disc, the intermediate points change the angle and magnitude proportionately between keyframes. In other words, if your first point is red and the second point at cyan, both at the edge of the disk, the magnitude of both points is the same (1.00), and the angle marches around the disk from about 106 to 284.

So the whole color disc metaphor is misleading when keyframes are concerned. Anyone know how do do this better?

PeterWright wrote on 12/4/2004, 5:19 PM
It may be the "smooth" setting is creating a curve between keyframes.
Try Linear and see.
riredale wrote on 12/4/2004, 11:28 PM
One obvious solution that has occured to me since the original posting last September is to create a series of intermediate points, forcing the dot to follow the path you want.