Many have reported the dreaded blue clipping problem that occurs specifically with LED lights (doesn’t have to be blue LEDs) in low light shooting conditions. Let’s see how to fix that on set.
What is blue clipping?
“Blue clipping” is the popular term that describes what happens when you see splotches of blue (it can be any color, really) when it should really clip to white.
Here’s an example of a shot that shows blue clipping on the left (notice the hair, and the border between light and shadow on the face), and what it should look like normally on the right:
This typically appears when you have strong blue lights as in night clubs, concerts, police cars, etc. Since the lights flash on and off, it’s hard to catch.
Watch my quick video on the correct techniques to fix this problem:
The tools to use
By changing the color balance (more below on how to do it), once you cross a certain threshold, you see the red and green channels drop. They don’t drop to immediately, but in stages. So, the blue clipping is caused by the red and green vanishing, while the blue stays where it is. That’s why you see blue. When it’s overexposed, it is blue-white.
If you see any other color clipping, then the opposite colors might be dropping, so you you know what to compensate for.
You will see the blue channel goes haywire, beyond permissible limits. This isn’t as helpful but it does show the blue color is off the charts.
Why does it happen?
Since this only happens with LED lights, the possible explanation could be that since LEDs have a blue spike in their spectrum, for some reason this throws off the pixels (called sensels) in the sensor. The pixels affected are no longer able to collect red and green information, and the result is too much blue.
How to correct for blue clipping
This is my main tool. Instead of setting a white balance automatically, or just picking one of the presets, try to manipulate it manually – if the camera allows you to.
E.g., if the clipping is blue in color, then move the white balance to the blue zone, which is greater than 5600K.
As you will notice, it only affects the area in contact with the LED lights. The other regions continue to behave normally. This is especially helpful in night club or concert video shooting where the rest of the background is pretty dark.
If you’re in a club or street and you start to see blue clipping, you might have white balanced to a Kelvin rating below 4500K. Try to change the white balance to above 4500K. This will change the colors of course, but they can be corrected in post. The blue clipping can’t be fixed.
The next thing to try is to manipulate color balance. You should typically find it in the profile settings. The color balance allows you to manipulate individual channels as Red, Green, Blue, Cyan, Magenta, Yellow. This gives you greater control to balance the other “dropping” colors so the blue doesn’t clip.
You should take care to do this slowly and only as much as required. With lower-end cameras, pushing these settings too far will have other undesirable results.
Last resort, try reducing the saturation of the image. This is not ideal, but it’s better than ugly blue artifacts. Only use if your camera doesn’t allow you do anything else.
I hope this helps and will fix your problem. If you know of any other solutions to this problem please let me know in the comments below.