Tuesday, November 23, 2010

Rays across the sky

The photo features an array of anticrepuscular-rays as observed in Kämpfelbach near Karsruhe, Germany on July 31, 2010. I will never forget this sight. Sunset was fast approaching, and I first noticed faint crepuscular-rays above the western horizon. Just after sundown, the rays could be seen stretching across the sky from west to east. On this photo montage, east is at left center and west at far right. This display lasted for about ten minutes. To add to the show, the rosy glow of Earth's rising shadow (belt of venus) and the shadow band itself were visible just above the eastern horizon (left center). These anticrepuscular and crepuscular rays were cast by clouds below the western horizon. Viewing perspective makes the rays seem to converge toward the horizon; though, they're actually parallel.

Photo details: Nikon D40x camera; 16 pictures in vertical-order; focus length 18 mm; F/3.5; 1/60 second exposure time; ISO 100.


The photo showing a classic cloud-to-ground lightning strike and a cloud-to-cloud bolt as well was taken at Kämpfelbach near Karlsruhe (southwest of germany) on August 22, 2010. Temperatures reached the mid 80s F (25-28°C) here by late afternoon shortly before a weather front and accompanying thunderstorm blasted through. The lightning was quite intense with this storm. I estimated 10-15 flashes per minute. Cloud-to-ground electrical discharges are typically observed when the base of the cloud is negatively charged and the ground is positively charged. On the other hand, cloud-to-cloud (inter-cloud and intra-cloud) lightning occurs most often when the top of the cloud is positively charged and the base negatively charged.

Photo details: Nikon D40x camera; F/9; 1/6 second exposure time; 18mm focus length; 100 ISO.

Dew bow

The photo above showing a sprightly dew bow was captured in a moist field crop at Kämpfelbach Germany on the night October 22, 2010. Since the photo was taken at night, the illuminating source is the almost full moon which is directly opposite of the dew bow at the anti-lunar point. The mechanics of a dew bow are similar to that of a rainbow. Moonlight is refracted and reflected within the dew drops. The city lights in the background are Karlsruhe.

Photo details: Canon EOS 450D camera; F/4; focal length 8 mm; ISO 100; exposure time 30 seconds; 3 photos stitched together.