Fixing Chromatic Aberration in Aperture 3
The Chromatic Aberration tool in Aperture corrects for lenses that do not perfectly focus all the different colors of light. This can lead to the different color channels being slightly misregistered or offset with respect to each other in the final image, and the visual effect is slight green/magenta or yellow/blue fringes near the sides of the image.
The Chromatic Aberration filter compensates for this color misregistration, bringing the color channels back into alignment.
A Nice Fall Day in New York
This picture looks like a nice fall day on the surface, but inside it lurks chromatic Aberration that we want to eliminate, or we risk seeing it when we print our images (or look at it large size, the first issue is clearly visible on a 30" Cinema Display). Zoom into your image with the Z key and then increase the zoom as needed.
First Chromatic Aberration
The first example of this aberration is on the white truck found where the arrow was pointing above. (Mac Create Premium Members can download the original RAW file for this example.) Notice the red and blue fringing on this white truck? That’s where the glass didn’t focus the different planes of light correctly.
More on the House
We see some other examples of this on the house in the shutters and the doorframe.
If we look at the center of the frame, we’ll notice no issues with chromatic aberration. That’s because it’s easier for the lens to focus the planes of light at the center, especially on super-wide lenses like this 16mm.
Select The Tool
From the Adjustments drop down in the Adjustments Inspector select Chromatic Aberration.
Drag Sliders
Fixed, Sort of
Dragging the slider toward the red made one of the sides of the van better, but the other side is worse. The solution here is to brush on our correction.
Select Brush
From the Action Menu (it looks like a gear) select Brush Chromatic Aberration in. Brush over the edge of the van.
Brush the House
Also brush the shutters in the house.
Fix The Other Issues
The other side of the van has a chromatic problem in the opposite direction, so we need to Add New Chromatic Aberration adjustment
Adjust the Sliders
Again, adjust the sliders until the problem you’re trying to fix goes away, but check to see if other problems crop up.
Other Problems Cropped Up
Here we’ve fixed the van, but the house is now going off. So we’ll brush this on as well.
Select Brush
Again select Brush Chromatic Aberration In
Brush Over Van
Brush over the edge of the van to fix that issue.
Corrected
The van has been corrected, now you’ve removed a good amount of the chromatic problems with this image.
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Author: David Schloss
David Schloss is the director of the Mac Create Network and the Aperture Users Network, a professional photographer, writer, editor and photographic educator who specializes adventure sports, travel and lifestyle photography. Schloss is the author of the books Blue Pixel Personal Photo Coach: Digital Photography Tips from the Trenches and Blue Pixel Guide to Travel Photography: Perfect Photos Every Time. Schloss is the former Technical Editor for Photo District News, a position he held for six years.
2 Comments
Chris (8 comments.)
March 3rd, 2010
Nice explanation of Chromatic aberration and how to eliminate it in Aperture 3. I’m new to Aperture with version 3 and I don’t have much formal photography training so I would have never figured this out by myself.
Zandr Milewski (1 comments.)
March 5th, 2010
It really seems like if you have to brush the correction in and out of the image, you’re not really doing the correction properly. I haven’t played with the tools in Ap3 yet, but certainly using PTLens or LensFixCI, I’ve never wished for a brush.
I wanted to try my hand with the image you used for the demo, but I can’t find the link in the premium section.