chromatic aberration and Nikon corrections

[hevans]

Hi,

I discovered just how much chromatic aberration (purple fringing) that was produced in the lens and then corrected by the Nikon processing software (ViewNX, or the on board software).

A silhouette taken at 18mm with the Nikon 18-200 general purpose lens seemed fine, until I loaded the raw file into PSPro and started to play with it. The fringing on the Raw file was considerable (5-8 pixels at the edges), but not at all evident in the processed JPG that went with it. Using ViewNX, I converted the raw to a 16 bit TIF, loaded that and the purple fringing was not in evidence at all - at least I presume it was done with the raw file and not the JPG...

I think in future, I'll convert to a 16 bit TIF as the first step in my "workflow".

Hugh.

[Hinfrance]

As I understand it Hugh the dedicated RAW converters that come in the box with most cameras these days are specifically set up to deal with not only CA but also the distortions produced by the lenses.

I'm pretty sure that DXO Pro, once loaded with the correct lens profiles would also do the job very well. Alas they don't seem to have any profiles for Tamron and Sigma lenses as yet, so I didn't invest.