I discovered something yesterday that I’ve never noticed before, and it completely knocked my socks off — but in a bad way — so I thought I’d post about it, so everyone can either learn from my experience OR laugh at me for never noticing it before!
The aberration is called: Purple Fringing. (It’s sometimes other colors, like magenta, but it’s most commonly purple.) I’ll go over how to prevent Purple Fringing and how to get rid of it, so read on…
What is it? Purple Fringing is when you get purple color in high-contrast boundary areas in an image that was most likely taken in low light situations. The actual color and tint varies based on the camera, the lens, the lighting situation, etc.
How can you prevent this? Get a UV filter for all of your lenses. Unfortunately, that doesn’t always resolve this aberration, but it can prevent it from happening some of the times.
My Image with Purple Fringing
I didn’t notice the Purple Fringing until I got my client’s print order from my lab. (Can you even see it here in this shot?)
[Note: I used a Nikon 14mm ultra wide lens for this shot. The lens is built like a tank and looks like a fisheye lens with it’s bulging curvature. It is not possible to put any lens filters on this kind of lens.]
Below is a close-up view of a section that has Purple Fringing. Arrrrrgh!
You can see it in various branches (like on the left side) and the edge of the roof (like on the right side of the image), but it was in so many places on the house and tree branches that I didn’t think this was fixable.
The Image AFTER Correcting the Aberration
Below is a close-up view of the same section.
I wouldn’t say it is “perfect”, but this is as good as it gets without changing the color of the rest of the image.
[Note: I have Adobe Photoshop CS4, so I can only tell you the exact steps for CS4. If you have another PS version, PS Elements or other editing software, but this may at least give you an idea of where to look.]
Steps To Correcting Purple Fringing (in Photoshop CS4):
1. In Photoshop, Click on “Adjustments” under the “Image” tab.
2. Select “Hue & Saturation”.
3. Where you see “Master”, click on it and select “Blues” to get to the Blue Channel.
4. Once you’ve selected the specific color channel, you will have the eyedropper tool.
5. Select the left-most eye dropper.
6. Then click on one of the areas with purple fringing. (I chose the tree branches on the right as they were one of the most prominent problem areas.)
7. Then go to the Saturation slide bar and move the slider to the left. Usually a place between -70 and -80 works best, but this depends on the image and the amount of fringing.
8. After correcting the purple fringing, check your image to see if you need to adjust anything else in your image as reducing the blue color may change the rest of your image or make it a little dull-looking.
So there, Purple Fringing!!!