Monday, March 23, 2009

Anticipating and Seeing a Circumzenithal Arc

I've been chasing circumzenithal arcs for some time. This is the first plainly visible one that I anticipated based on the conditions: sun low in the sky, cirrus clouds passing overhead, and no clouds dimming the sun. The photo below was taken about 1 minute before the arc formed using the maximum field of view for my 18-55mm focal length lens and has been cropped in width.

Friday, March 13, 2009

Moon and Venus, visual and in binoculars

Click on the above photo to see it in full size. It shows two photos of the Moon and Venus photographed on February 27, 2009. The inset was photographed through a small telescope that at prime focus gives a magnification comparable to what you get with 8-power binoculars. I was surprised to see the crescent of Venus in the photo.

Though I've seen the crescent of Venus many times at high power through a telescope, I rarely look through binoculars at a time when the crescent is at its largest size.