DXO is currently offering 30% off DXO Optics Pro 6, so I thought I'd download the trial version and compare how well it removes chromatic aberration from my Tokina AF 10-17mm f/3.5-4.5 AT-X DX Fisheye lens. The latest version of Adobe Camera RAW (ACR) also includes Lens Profiles for automatic chromatic aberration correction, so I thought I'd see how well ACR works in this aspect as well.
I processed two images (NEFs taken with the D200 and Tokina 10-17mm fisheye) through DXO Optics Pro 6, ACR 6.2, and Capture NX 2 (which is my usual choice). I converted the NEF in all three programs with no sharpening.
For this first image, I processed it in all of the programs both with and without automatic CA correction.
In Capture NX 2 I converted with the default settings (but no sharpening).
In ACR I also converted with default settings (but no sharpening). There wasn't a lens profile available for the Tokina AF 10-17mm f/3.5-4.5 AT-X DX Fisheye lens, so instead I used the profile for the Nikon AF DX Fisheye-Nikkor 10.5mm f/2.8G ED lens. I set the Distortion and Vignetting corrections to 0 and left the CA correction slider at 100.
In DXO Optics Pro I converted with all the options unticked other than Auto CA correction. I also made another conversion with the PF removal checkbox ticked as well.
This is the image I used for testing:
And here are the results, all cropped approx 200% from near the top left corner:
As you can see from the images with no correction applied, the lens has a bit of chromatic aberration. All three programs process the image very similarly with regards to how the chromatic aberration and purple fringing is rendered when no correction is applied.
I was surprised at how badly DXO Optics Pro 6 handled the CA removal. Although it does make a slight improvement compared to processing the image with no correction, the chromatic aberration is still easily visible. I double checked that DXO was loading the correct profile for the D200 with Tokina 10-17mm fisheye when processing the image, and it was.
Checking the automatic purple fringing removal checkbox in DXO didn't seem to make any difference with this image.
Adobe Camera RAW 6.2 doesn't have a lens profile available for the Tokina 10-17mm fisheye. I did try to see if anyone had produced one themselves, but couldn't find anything. You can see in the image that the Nikon 10.5mm fisheye lens profile I used instead works quite well. There is a tiny bit of over-correction (leading to a slight red fringe) I would say, but you can easily adjust the amount of correction in ACR.
Because the Nikon 10.5mm lens profile is for a fixed focal length lens, but the Tokina fisheye is a zoom, I think you would need to manually create a profile for each focal length, as the amount of CA correction needed is likely to vary with focal length.
Lastly we have Capture NX 2, and you can see why this is my choice in converting Nikon NEFs. It removes the CA completely.
This image was processed in a similar way to the first one. In DXO I had both Auto CA correction and purple fringing removal checked. In ACR I used the 10.5mm Nikon fisheye lens profile again, but also used the automatic defringing, set to 'All Edges'. Capture NX 2 doesn't have a PF removal option, so just the Auto Color Aberration was checked again.
I took two 200% crops from different points in the image this time, to show both the chromatic aberration correction and also purple fringing correction. This image shows where the crops were taken from:
Crops showing auto CA removal:
Crops showing auto PF removal:
I would say that with this second image, taken at 10mm instead of 11mm, DXO Optics Pro 6 seems to do much better at automatically removing the Chromatic aberration, though probably still not quite as good as ACR 6.2 or CNX2. DXO does a great job at removing the purple fringing though. I also noticed there is a strange sort of colour moire pattern happening in the grate below the railings in the DXO image.
When processing an image taken with the Tokina fisheye at 10mm, I would say that ACR with the Nikon 10.5mm fisheye lens profile corrects the CA perfectly. The defringing does quite a good job at reducing the purple fringing, though not as good as DXO. I found that setting defringing to 'All Edges' does a better job at removing the PF than the 'Highlight Edges' defringing setting.
Again, Capture NX 2 does a great job at removing the CA. Unfortunately it isn't too great at removing purple fringing.
I don't think I will bother purchasing DXO, but will continue using Capture NX 2. Purple fringing can be removed relatively easily be desaturating purple / magenta colours using a Hue/Saturation layer in Photoshop.