Canon 30D, handheld
[Top] Tokina 19-35 at 19mm, f5.6
1/640 second at ISO 200
[Bottom] Mamiya 80mm at f4
1/3200 second at ISO 200

 
Doesn't fit the pattern
circumzenithal arc

While out with the Immaculate Mr Bugg one fall morning, he looked nearly straight up and said, "Hey! There's a rainbow up there!" I followed his gaze, expecting to see a sundog, those little splotches of refraction that can be seen to flank the sun in certain conditions, because there was no way that a rainbow would be found in the direction he was looking. But he was more-or-less correct. Here's the thing:

Okay, the classic rainbow always appears opposite the sun, because that's how the effect works. And they can only appear when the sun is below a certain level 10:30 AM does not qualify. Had I thought for a second, I would have known a sundog was also out of the question, because they would have been a lot lower than this as well. However...

... there's a phenomenon called a circumzenithal arc because, well, the arc forms around the zenith, meaning the radius of the arc is straight up, even though the arc itself isn't quite. They're pretty rare, requiring just the right conditions of high-altitude ice crystals and the right sun angle, so we were lucky to have these for about 15 minutes where we could endeavor to get a decent view of them. Since we were in deep wooods at the time, it required finding gaps in the trees, but at least the display was pretty bright

Shooting any kind of rainbow or refraction can be a little tricky. Trusting the camera's exposure meter is not the best of moves, so bracketing heavily is recommended, as is using increased saturation and contrast settings. And don't hesitate; the conditions usually won't last long. of course, doing something creative with the composition, while preferred, can be very difficult. The arcs are only going to appear in one small region of the sky and you'll be extremely lucky to have something in that direction to work with to add more to the frame than simply the arc itself.

circumzenithal arc through leaves