Many have reported the dreaded blue clipping problem that occurs specifically with LED lights (doesn’t have to be blue LEDs), in which the blue channel “clips” to an ugly blue color. This doesn’t happen with all LED lights, but just a few specific types.
First, watch this super-quick video to see what’s happening:
RGB Parade – I’m changing the white balance setting. Once I cross a certain threshold, you see the red and green channels drop. They don’t drop to 0 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.
Vectorscope – This is the tricky part. You can see how the blue channel goes haywire, beyond permissible limits. Again, I’m changing the white balance and no other setting.
White balance – From 2600K to 4500K, the blue clipping problem can occur. Once I hit 4500K, the clipping goes away.
As you can see, it only affects the area in contact with the LED lights. The other regions continue to behave normally.
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 Sony sensor (the same problem is said to exist in the FS700, FS7, etc.). The pixels affected are no longer able to collect red and green information, and the result is too much blue.
I’m not sure this is a solution, and I’ve only been able to test it with the LED lights on the back of my LED lighting panel (it’s not a “blue” LED, it’s a white LED that looks blue. A blue LED is a specific type of LED that got its inventors the Nobel Prize a year ago).
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.
If I find something else I’ll let you know. If you do find a solution please share it and I’ll publish it.