November 07, 2010

Funny light effects explained......we think

It has been bothering me not to understand what’s going on with the light here. Actually, it has been nagging at me ever since I put up that last post. But this morning my attention was diverted away as I tried to work out the new time difference due to the end of Daylight Saving Time today in the US.

I looked online for a definitive time-of-day site so I could be absolutely certain of the new time difference between Windhoek and Albuquerque. I have become hyper-attuned to always knowing that difference so that I don’t repeat an earlier offense of wanting to share something with my daughter via text message at the exact moment I think of it. That resulted in a message that reached her at 3AM her time. It was not well received.

I found a site that gave not only the time but all sorts of data about day length, phase of the moon, civil twilight times, AND the sun angle at noon. As it turns out, the sun angle in Windhoek was 84° above the horizon at 12:35 PM today. That little data point pretty much explains the amazing light effects we have been seeing through polarized sunglasses and polarizing filters.

According to the professor, the best effects with a polarizer (and polarized sunglasses) are when your line of sight is 90° to the sun. Near noon the sun is so close to directly overhead here that if you look straight ahead, wherever you point your polarizing camera filter or your polarized sunglasses, your view is virtually 90° to the sun. Thus, the gorgeous light effects we have been seeing here lately.

Since Windhoek is about 54 miles north of the Tropic of Capricorn where the sun is directly overhead at noon on the December 21st summer solstice (winter solstice at home), there should be these same awesome photographic opportunities and great light effects for a few weeks on both sides of the solstice.

That’s something to look forward to on your trip here, Erin. (I would have put that in a text message to you but I may not have this time difference thing worked out yet.)   :>)