One of the main tricks of the Huawei P20 Pro cameraphone is lightpainting. Using AI technology, the phone is capable of creating minutes-long exposures that allow for extensive “painting” without overexposing the background.
It does this by taking a reference image to gauge a base-level exposure and then processes light-movement in virtual layers – keeping the rest of the scene dark. This means that "painters" can walk around while in shot and be automatically removed from the final picture. To some extent, shots can also be created whilst handheld, although in our experience it was always better to have a solid base.
Nonetheless, the effect is impressive as the following photos show.
Swinging a changing-colour light around in front of the Huawei P20 in lightpainting mode.
Resting the camera on the Sydney Harbour Bridge while creating a 2-minute exposure in lightpainting mode.
There are different kinds of lightpainting mode. This is optimised for car light trails.
There are also modes for star trails and silky water effects. This is car lights again.
Handheld while an artist swung a light around at a matched shutter speed to create the Huawei logo.
It didn't always work as we hoped. There are plenty of disembodied arms visible here.
To capture this scene automatically (when it was effectively dark outside) is impressive. But note Luna Park in the distance.
Yes there are sharpening effects but yes that's also 10x zoom in low light. Impressive.
Related: Huawei P20 Pro Full, in-depth review