The Monaco UFOs
Case file #116121
“During a trip to Monaco last year with my mother, we took some pictures while touring the palace grounds and surrounding areas. Upon inspection, we noticed some strange lights in the pictures. I was using the ‘sports’ mode in my camera then and it captured a series of pictures in one click. The lights in the pictures could be seen in different angles and at different times. We stayed at the Fairmont Hotel then and the hotel manager suggested that we send the pictures to the press which were later published on their Facebook page (link: https://www.facebook.com/media/set/?set=a.10150507695743831.378183.119207753830&type=3). We have many more of these pictures. We also showed these pictures while in Monaco to the police and they were equally puzzled. One of them pointed out that they could have been caused by the street lights (?!). It has been a year since we took these pictures but have yet to receive a decent explanation. Any input is much appreciated”
Having looked at the images in detail I was able to ascertain that the light anomaly in this photo is caused by lens flare.
Flare is particularly caused by a very bright light source in an image – which produces the visible artifacts witnessed in image one. Lenses with large numbers of elements such as zooms tend to exhibit greater lens flare, as they contain multiple surfaces at which unwanted internal light scattering occurs.
The spatial distribution of the lens flare typically manifests as several starbursts, rings, or circles in a row across the image or view. Lens flare patterns typically spread widely across the scene and change location with the camera’s movement relative to light sources, as appears to be the case in images 1 and 2.
In image 3, the spatial distribution of the flare would suggest that the bright light source on the left of the archway is the cause for it.
The colouration of the flares being different to the primary light source is due to chromatic aberration. Anti reflective lens coatings are meant to reduce the reflection levels of unwanted flare effects. However, they cannot eliminate it entirely. Lens flares often appear as hues of yellow, green, blue-gray, red, and violet and can appear quite ethereal in dramatic photos such as in this case.
You will also note that not only is the colour of the flare the same in all the pictures above, but that it also has the same shape. This is due to the shape of the camera’s diaphragm – which are often polygonal. It is the shape of the internal diaphragm which determines how the flare will appear in the photo.
If you look closely at the comparison image below of a known lens flare you will see the remarkable similarities.
Based off the evidence, I have no hesitation in declaring the Monaco photos as a lens flare phenomenon.
© David Calvert 2013
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