Let me translate the alphabet soup: WP means weather (or water?)
proof, IS means image stabilized, and L means Canon's L-series lenses
for the objectives. These lenses apparently contain ED elements, and
supposedly reduce chromatic aberration.

Anyone try them out yet on a bright glint to see if it really does
help?

Brian Tung
The Astronomy Corner at http://astro.isi.edu/
Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/
The PleiadAtlas Home Page at http://astro.isi.edu/pleiadatlas/
My Own Personal FAQ (SAA) at http://astro.isi.edu/reference/faq.txt