I was out at a star party last night in Sells, Arizona. The western horizon behind some trees so I didn't really expect any great photographic opportunities. I stepped outside a couple of minutes before sunset and based on experience, thought the Sun looked like it might produce a green flash. I didn't even have my tripod with me so I had to hold the camera by hand (forutnately, using very short exposures you can get away with that!) I had very little time to adjust the settings and think these would have been even better with just a touch longer exposure. Still, I was quite happy to get a unique shot through the tree branches. Here are the pics.
Visibly, these were bright and distinctive green flashes. I saw one on the left and one on the right as the Sun was bisected by tree branches. I showed photos to people at the star party and lots of them didn't even know you could see a green flash from Arizona, subscribing to the mistaken notion that you had to watch sunset over the ocean.
Reprinted with permission from the Half-Astrophysicist Blog.