Have you ever experienced colour fringing in blue sky. This is also known as chromatic aberration or purple fringing and is a common optical problem caused by the failure of a lens to focus all colours to the same convergence point. The best way I have found to correct this problem is in lightroom. There was of course a new enhancement brought out in lightroom 4 called the new colour fringe correction controls which I used in the shot below. What I found particularly useful was the colour section where you can select the eye dropper, sample where the purple fringes are and further correct this problem. By also adjusting the noise reduction controls I noticed a remarkable improvement especially with adjustments of the luminance slider and the colour and detail slider which then completely removed all purple fringing in the case with the shot below. As a result of all this a moment in time is captured of the construction of the Sydney Barangaroo Casino.
