Hawaii has a love-hate relationship with “vog.”

On one hand, vog (or volcanic smog) is basically harmful volcanic air pollution. As Kilauea volcano on Hawaii’s Big Island oozes lava, it emits sulfur dioxide that reacts with sunlight, oxygen, dust particles and moisture to form an aerosol, better known as vog.

When this vog wafts over the islands, it often leaves people with headaches, watery eyes, sore throats, and can make it very difficult to breathe. (It’s like being in a smoky room, but it’s everywhere.)

On the other hand, vog is the world’s best real-life photo filter. When sunlight (or moonlight) passes through the vog-polluted air, it can create some truly mind-boggling horizons.

In short, vog is bad for your health, but oh-so-good for brilliantly colored — or ominously muted — skylines.

via Hawaii Vog Makes For Incredible Skylines And Horrible Air Quality.