Laser Test

To strengthen the conclusion in 3) that the image of the ball of light is not the result of an image produced by a laser, was first characterized the response of the CCD camera at three different laser wavelengths: λ = 635.6 nm (red), λ = 543 nm (green) and λ = 594 nm (yellow-orange). The images were projected on a white background.

The results of RGB analysis are shown in the figures below.

RGB red laser analysis

RGB green laser analysis

RGB yellow-orange laser analysis

As we can see, the responses of the CCD are consistent with the behavior expected for a monochromatic source. In particular, the response to a red laser light shows a dominant component of R, but also a small component of G and a B component negligible. The sensitivity to green is superior to that of blue.

The response to the green laser is very satisfactory being the dominant component of G, only a little saturated, always well above the other components R and B these not giving a contribution, being below the background level.

The response to the laser yellow-orange, shows the dominant components R and G, with a low contribution of B, as expected.

The next test was the projection of the image of the red laser in the same area and environmental conditions of original observation of the ball of light. On the spot we took several images of the laser with different backgrounds to see the response of a RGB analysis to a plane diffused reflection image of a laser. The image distance is 17.6 meters. The figures show three frames selected from video with three different backgrounds.

Rock type background

RGB analysis

Non-turbulent water layer background

RGB analysis

Turbulent water background (saturation for R)

RGB analysis

Turbulent water background

RGB analysis

Comments
The RGB analysis clearly show that the projected image of a laser show a different RGB response depending on the backgrounds considered. It is therefore transparent in the visible. This analysis shows that the ball of light recorded by video camera, with peak emission constant and nearly independent from the background, cannot in any way be attributed to the light reflected / diffused of a monochromatic laser.