Canon G1X Mk3 Managing color fringing in Adobe Camera Raw. 10 April 2018

The G1X3 is a good street/documentary camera with fast accurate focusing. There is a bit of blue in the flare around the lights which I elected to leave in place.

The Canon G1X3 is a versatile compact camera  capable of delivering very good photos in a wide variety of circumstances.

However the Raw files exhibit purple fringing in some conditions, please refer to the photos below.  JPGs are less affected by the fringing but it still can be present for instance in the JPGs of the images below (not shown).

In my experience of several thousand frames with the G1X3 the most likely scenario to produce color fringing is foliage against a cloudy bright sky but any similar condition with high subject brightness range across an edge can do it.

Last week Adobe released an update of Photoshop and Camera Raw with a revised and expanded Profiles facility including Camera Matching profiles.

I have been experimenting with these to determine whether they are useful for managing the fringing.  My results are not encouraging thus far.

It seems to me that there is no “right” treatment for all files and the best approach is to tackle each one separately. The nature of the fringing is different in each case. Sometimes it is blue, sometimes purple or magenta and sometimes there is green fringing on the opposite side.

This is a crop from the top right of the photo below, showing typical color fringing.

The whole frame. There is plentiful color fringing in the upper part of the frame with foliage against a cloudy/bright sky.

So I will just put down all the strategies that I have discovered with some notes as to their usefulness in my experience.

1. Global strategies, that is, affecting the whole frame.

1.1.  In the Basic tab of Camera Raw the default Profile is Adobe Color. But there is also a set of Camera Matching Profiles. I tried all of these with various files and found that the Camera Faithful Profile gives less color fringing with some images than the default profile.

But, I also discovered that with some images this does not eliminate color fringing.

So I tried to correct the residual fringing by going to the

Lens Corrections Tab>Profile>Remove Chromatic Aberration. Unfortunately in some cases this actually made the color fringing worse by adding magenta fringing to the residual blue/purple fringing.

1.2.  Reset the default profile (Adobe Color) in the Basic Tab.

In the Lens Corrections Tab go to Profile>Remove Chromatic Aberration. This usually removes some but not all of the color fringing.

1.3. Still with the default Adobe Color profile in the Basic Tab, go to the Lens Corrections Tab>Manual>Defringe> see options for purple and green fringing.  This is more effective at removing color fringing than the strategy in 1.2.

But full correction of fringing by this method can with some images cause the phenomenon of gray fringing elsewhere in the frame. When present this is particularly noticeable on human skin and is highly objectionable.   This problem can occur to some extent with any camera/sensor/processor system but is more obvious with the G1X3 than any other camera which I have used.

2. Local strategies.

2.1.  Select the Adjustment Brush in Camera Raw. Look down the list of settings which can be applied to the brush and find Defringe. Set the amount  arbitrarily to 50 and swipe the brush over the part(s) of the image with color fringing. Adjust the amount up and down, see what effect this has.

I find that some reduction of fringing can be achieved this way.

Summary  I am unable to offer a method which works reliably with every image.

My own practice is to set the default Adobe Color Profile in the Basic Tab then in the Lens Corrections Tab go to Profile>Remove Chromatic Aberration,  then if there is residual color fringing I select the Adjustment Brush with Defringe and apply local correction.

This appears to work reasonably with most images but I sometimes find that I end up having to tolerate a bit of residual color fringing around the edges of the frame.