Dewbow

Dew bows are a kind of rainbows. The difference lies in the plane of projection and in the fact that static droplets are reflecting the refracted light back into the eyes of the observer. The rainbow cone resulting, the apex of which is the oberver´s eye, is cut by the plane (the field). The result is a hyperbola, but for our eyes, there is always a circle!.

The first nights in October were rather cold, so that a lot of dew could form in the fields.

I knew that the following days were ideal for looking for the dew bow.

The main problem while observing dew bows is the brightness of the field. A polarization filter makes the dew bow contrast better from the background. (2)

An even better idea was filming the dew bow while driving along the farm track. This makes it contrast even more clearly.

Place : Neulingen, Germany
Time : 02 October 2011
DSLR Camera : Canon EOS 450d
Exposure : 1/25 sec, f/10mm, F/7, ISO 100

Author: Michael Großmann, Kämpfelbach, Germany

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Heiligenschein and dewbow in moon light

Well, I wanted to observe moon halos that evening, but the sky was totally clear without any cirrus clouds.

I noticed that some blades of the plants on a field were rather wet. I walked some steps into the field and immediately noticed a clear brightening around the shadow of my head. I did a few steps to the left and to the right and could see a very faint dew bow. So I took some photographs at different exposure times and ISOs. The best photographs (1 2) I achieved using stop 4, an 18-mm-lens and at a time of exposure of 45 seconds at ISO 400.

Author: Michael Großmann, Kämpfelbach, Germany