A NEW LOOK AT CHROMATIC ABERRATION
Thought I would share a tip that can really improve your photos, especially landscapes. Wikipedia says “Chromatic aberration manifests itself as “fringes” of color along boundaries that separate dark and bright parts of the image.” This seems to be very apparent in blue skies in landscapes with lots of trees. The above image was taken at the Jacksonville Zoo of a vintage-looking carousel (see my Only in Florida! Tidbits Blog for a closer look). Just a few Basic panel adjustments Lens Corrections (checking just the Enable Profile Corrections and Remove Chromatic Aberration boxes) were done in Lightroom before opening up Photoshop.
This technique was passed along by one of my favorite Photoshop people, Blake Rudis (who says he learned it from Steve Perry), at his f64 Academy in a video called The Color Blend Mode – there is a free downloadable action here to do this technique. The image had some empty branches against the blue sky along with was some real blue-cyan chromatic aberration. In Lightroom the Remove Chromatic Aberration checkbox did not remove this and to be honest, I did not notice it until I was in Photoshop since only the upper corners were affected. Below it can be seen what a subtle difference the technique makes – you can definitely see the cyan color shift due to the Chromatic Aberration in the sky. It is hard to see, but the branches on the right side image look a bit darker and sharper, especially where the larger branches are present. This was also true on the upper left side of the image.
So here are my steps to get rid of this ugly blue edging in this case but it will work on any color of chromatic aberration.
- Duplicate the Background layer (CTRL+J) and turn it into a Smart Object by right clicking on the layer text area and selecting Convert to Smart Object. A stamped layer (CTRL+ALT+SHIFT+E) could be used and duplicated if in the middle of post-processing.
- Go to Filter -> Blur -> Gaussian Blur and set the Radius somewhere between 6 and 20. I used 6.8 for this image.
- Change the layer blend mode to Color – now the whole image is blurred.
- Click in the Smart Filter layer mask and CTRL+I to turn it black. With a regular soft round brush, paint with white just in the areas you want the blur to correct the chromatic aberration.
Blake does not use a Smart Object, just applies the filter and adds a black layer mask – then paints back areas that need correction. This technique also works if the chromatic aberration is not completely removed when using the Camera Raw filter. What is really useful is that this is a localized correction and only affects the part of the image that needs the correction. The Blur does not affect the whole image! I find this gives a very subtle and sharp result to the bad areas. Here is a link to one of my Tidbits Blogs called Defringe that Nasty Blue Edge from Trees On a Bright Blue Sky! done a while ago where 4 other ways to remove Chromatic Aberration are presented if you would like to try out some other techniques.
There were lots of steps used for final processing in this image – Topaz (see sidebar at my Tidbits Blog for website link) Glow, Topaz DeNoise, Photo Filter Adjustment Layer, Vignette, and clean up layers. Overall I was pretty happy with the final results.
Give this Chromatic Aberration trick a go, especially if you have cyan blue going around those branches in trees. It works really great! Also check out Blake’s f64 Academy website as he has lots of great ideas on improving pictures. Well, back to my organizing until next week…..Digital Lady Syd