Thursday, April 28, 2011

Light and Water: Post Eight

So far in my own inquiry into water and light, I've really been focused on understanding the role of viewing and illumination angles. Here are some ideas I'm more and more committed to:
  • Shallow or glancing angles tend to reflect more off the surface of the water (like a mirror), This makes it so that being down by the lake you are more likely to see reflections, whereas being up high (looking down) on a lake you are less likely to see reflections. This relates to post two and post five
  • A low sun behind you illuminates strongly the objects across the lake that are to be reflected, but the sun light only hits the lake with glancing blows (which mostly reflect away from you). The combination of strong illumination on the object and low levels back scatter from the sun make it easier to see the reflection.
  • On the other hand, a high sun hits the water with more penetrating rays (not glancing), which refract into the water. In many cases, that light scatters off particles suspended in the water, which go off in all directions. In this case, the high amount of scattering creates noise that overwhelms any mirror reflections.
These last two bullets seem to concern post one and post seven

But there certainly is a role to be played by wind roughing the surface and the polarizing filter on my camera. So here are some photos that I think speak to this:

Here is an example I do think is likely wind, although glancing angles could still helping. This was also taken on Kidney Pond at Baxter State Park, looking toward Mt. OJI. I'm still doubtful that wind can fully account for this phenomena I posted about with the receding mirror boundary, but my mind is still open.

Here is one that I think has an effect from the polarizing lens (compare the real sky to the reflected sky). This photo was taken from the Stillwater River by the University of Maine.

I promise I'll get back to posting about teaching soon, but for now, I'm happily sharing my inquiry with you.

No comments:

Post a Comment