It is not a feature that every lens is graced with. The ability to bring all wavelengths of color into the same convergence point is ideal with optics in photography, however when these wavelengths of color meet at different positions, the result is chromatic aberration (or color fringing).Purple color fringing
Typically a result of a certain focal length or aperture setting, if you ever happen to come across color fringing in a photo you’ve snapped, here is a simple solution on how to fix it using the HSL panel and edge aware masking technology in Topaz Clarity. (If you don’t own a copy, download a free 30-day trial here.)
Here is the image I’ll be starting with. Camera settings are as follows:
- Exposure: 1/640 sec at f/1.8
- ISO: 250
- Lens: Canon EF 85mm
- Camera: Canon 5D Mark III
Although programs such as Lightroom, Adobe Camera Raw and Photoshop offer viable solutions for removing chromatic aberration, here’s another technique you can use to remove color fringing. It’s not the better of the techniques per se, however one advantage is that Topaz Clarity’s edge aware masking is something neither Photoshop or Lightroom offers.
Step 1: HSL Panel
- To start, open your image in a compatible host editor. If using Photoshop or a program that supports layers, be sure to duplicate the layer (cmd/ctrl + J) before opening Topaz Clarity.
- Open Clarity and press ‘Reset’ in the bottom right corner to rid the image of any effects that were applied in a previous session.
- We’ll now be working with the selective parameters on the right hand side of the screen. The ‘Clarity’ module is expanded by default, so collapse it by clicking on the arrow next to the name.
- Once you’ve collapsed the Clarity panel, expand the ‘HSL Filter’ panel under the ‘HUE / SAT / LUM’ module. Your screen should look like this:
- Now that our workspace is ready, under the HSL Filter panel, click on SAT, short for Saturation. Here is where you can selectively de-saturate individual colors within your image.
- It helps to zoom in here, so press the + key and use the spacebar to maneuver around the photo.
- Reduce the saturation of the colors shown in the fringing. I reduced the blue, purple and magenta sliders to desaturate the chromatic aberration.
As you can see above, the purple fringing has been successfully removed.
Step 2: Edge Aware Masking
Now that the chromatic aberration has been removed, we will now work with Clarity’s edge aware masking to mask back in the colors in areas where there is not fringing, i.e. the blue jeans which have been desaturated.
- Press the – key to zoom back out. You may notice that other areas will be affected in your image. Press the spacebar to view before and after.
- Underneath the HSL panel, expand the module titled ‘Masks’. Please note that there are two masking modules within Clarity. One pertains to the HSL module and the other to the Clarity module. Make sure you are working with the masking module underneath the HSL panel, not above it.
- Next to brush, choose ‘Edge Aware’. The edge aware brush is a smart brush that detects the edges of the area you are masking. Be sure to keep cross hairs of your brush on the area or color you want to effect and the brush will not bleed into any other areas.
- You may also choose to adjust the strength, brush size and hardness as desired. Brush over the color in your image you wish to bring back.
- If you make a mistake, select the ‘Reveal’, or white brush, to bring back the effect. This essentially acts as an eraser…black erases white and white erases black. If the strength is set to less than 1.00, you’ll get gray areas during the masking process, meaning there is opacity in the effect.
Here’s an example showing the successful removal of color fringing using Clarity:
Here’s an example that didn’t work so well:
This is a problem here as the skin has been desaturated. If you own Photoshop or a program with a clone stamp tool, this is an easy fix.
- Select the quick selection tool to do a quick outline
- At the top of the Ps menu bar click on
- Under ‘Adjust Edge’ increase the Smooth slider just a tad. This will ensure that there is not a harsh transition in the selection.
- Select the clone stamp tool and reduce the opacity to around 75% or so for better blending (access the opacity in the top menu bar).
- You can then bring back the skin color that has been desaturated with the clone stamp tool. The quick selection will work as a boundary.
- If you want to invert that quick selection to work with what’s on the other side, simply go to the top menu bar and click on Select-> Inverse.
- When done working with the quick selection, press Ctrl/Cmd + D to remove the marching ants.
Here’s a another before and after:
You might be thinking, “Why didn’t you just use the quick selection tool from the start to remove the chromatic aberration?”. Yes, there are many tutorials that cover this method and it does work in many instances. However think of the bike necklace shown earlier…it was much easier to remove the purple fringing using Clarity than to carefully select that with the quick selection tool.
Any other tricks you can think of for eliminating chromatic aberration? Be sure to share your results with us on Facebook.