How I managed to live (mumble, mumble) years being unaware of sundogs, I'm not sure.
It's been two years since I first saw one (and wrote about it), and I've seen dozens since.
But I still haven't managed to get a good photo of one.
I see them more often in winter, especially when driving south late in the afternoon. (AL-75S gives great sundog.)
No use trying to race them home, though. They're slithery, and don't hang around for portraits.
Here's a nice, simple page with a good sundog photo, as well as other atmospheric phenomena. Here is the definitive page on the science behind the "why" of all the optics.
The latest I and the Bird is up over at The Birder's Report. Go see!