[alexbock]

> (This is mathematically worse for a reason I don't remember; it causes any picture taken at a concert with blacklights or blue spotlights to look bad.

The iPhone camera sensor is prone to saturating and clipping the blue channel when strong light from a blue LED is in the frame. Once the blue channel clips at the maximum value, a typical HDR gain map won't do anything to restore more nuance to it because they're not designed to add high-frequency detail to a blob of clipped pixels with identical values in the base image.