And less leftover, or 50% off, Halloween candy. 

Apparently, this is the key to being able to see the colours of the aurora on quieter nights.
So although it's not especially common, it is especially fun, to be with guests who have very sensitive eyes and can sense and see those pinks and reds that are often more difficult for our eyes to see. Cameras, of course, tend not to have the problem of needing to eat excessive amounts of vegetables in order to achieve this.