One of my lights is pixelated... why?

Please see attached.

All of my other lights look fine, but this one b u g g e r is all about the pixelation. You can see in the image the rest of the lights look great.

I’m using Exponential Height Fog/Volumetric Fog.

EDIT: After some digging, I found out that all of my lights seems to be terrible quality, but I couldn’t tell unless I got behind them. It seems there is a distance resolution thing going on but I want to know where I can adjust the quality and detail falloff of the lights.