Flashes

I had a completely different blip planned but as we know, there's always the chance something more interesting - and better will cross our paths.  First I had the camera set up facing the back of the house because I had seen the flashes over the mountains on my drive home from Tucson.  I waited but nothing happened.  As we were eating dinner in the front of the house,  Mom had a great view of the sky (the window I was looking through faced the garage) and kept saying 'wow' with every flash.   I decided to move the gear there and nabbed these shots. I was pretty excited to get several.  I don't use timers or anything, just my itchy trigger finger.  To be honest, these were all the tail end of larger flashes, but they still fill my quota of one capture per monsoon/year (at least for the past three).

Anyone know of a scientific reason why a pinkish glow is created in the vicinity of lightening?