[This is my seventh post on the Rokinon 12mm F2 for Sony NEX.]
Like vignetting (see prior post), I feel that the purple fringing seen in the images below are all part of the nature of a third party ultra wide angle lens that has no electronic connection to the NEX camera body. I don't know for sure, but I don't think this lens performs any less well than would native lenses; it is just that there is no way for the incamera processing to eliminate the Rokinon's vignetting and purple fringing. However, it is generally an easy (but extra) step in post-processing to make appropriate corrections.
The purple fringing is very prevalent. It is visible in each of the four images below. These were taken at F2, F4, F8 and F16. Further below I have shown 100% crops from each one. Though I am choosing to make corrections in Lightroom, in most images it really won't make a difference when viewed at normal viewing sizes.
The four images taken (F2, F4, F8, F16)
The four 100% crops
|The four crops that follow are taken from the area of the|
original image circled in red.
|F2 100% crop|
|F4 100% crop|
|F8 100% crop|
|F16 100% crop|
How to fix this
What to do? Well, in Lightroom, things are made easy. Just a click of the check-box for "Remove Chromatic Abberration" and most of the work is done. For a portfolio image, you might want to instead play with the eyedropper to fine-tune things.
|F8 after applying Lightroom "remove chromatic abberation" tool.|
This is far better, and remember this is a 100% crop.
If that isn't good enough
|Here I have used the eyedropper tool as well as the automatic removal tool|
|F8 with "remove chromatic abberration" tool,|
plus customized removal with eyedropper.