Summary: A new study looks at how visual illusions play on pre-conceived notions people have about objects.
Source: University of Lincoln.
Whether it’s a blue and black dress – or white and gold depending on your take – or a pair of legs streaked with white paint, eagle-eyed viewers are always keen to debate a visual illusion when these puzzling images appear online.
A new study published today reveals the science behind another ‘trick of the light’ that made high-profile photographs of a major piece of public art appear ‘faked’ to some people despite the pictures being entirely genuine.
Vision science researchers from the University of Lincoln examined photographs of the art installation, Blade, which took pride of place in the centre of Hull earlier this year. Their interest was triggered when some pictures published online of the work – a 75-metre long, 25-tonne wind turbine blade – made the object appear to be super-imposed.
The researchers found that this visual illusion was caused by the particular way light reflected from the blade, which then played on pre-conceived notions people have of how objects are lit in natural settings, effectively altering the object’s shape to the human eye.
Daylight hitting the object from above produced shading which created the illusion that the blade was cylindrical, and was being lit from the side rather than above. This subtly reinforced the visual impression that the blade was out-of-place, and that the image of the blade and its backdrop must therefore be a composite of two different scenes.
To demonstrate this, researchers created virtual versions of a cylindrical C-shaped profile and a more complex S-shaped profile, and produced two images of each shape, one lit from above and the other lit from the front. The images demonstrated that the S-shape when lit from above and the C-shape when lit from the front both appeared cylindrical.
Professor of Vision Science, George Mather, from the University of Lincoln’s School of Psychology, said: “I saw pictures of the installation in the media, and at first sight the photographs seemed to be clumsy fakes. Something else seemed to be at work too, at least to my eyes as a vision scientist.
“The blade appeared to be a cylindrical object, strangely out-of-keeping with the local environment, lit differently, as though it was superimposed on the scene digitally, but it really was there.
“We had an idea about what it was that conveyed this impression – light and shadow on the blade which is apparently inconsistent with the surroundings. The computer generated images were a way of testing the idea.”
The blade was made by turbine manufacturer Siemens and placed in Victoria Square as a major public art installation to mark the start of Hull’s year as the UK City of Culture 2017. Artist Nayan Kulkarni created the installation for Look Up, a programme of temporary artworks designed for Hull’s public spaces and places. It used one of the first B75 rotor blades manufactured in Hull.
Source: Cerri Evans – University of Lincoln
Image Source: NeuroscienceNews.com image is credited to Professor George Mather, University of Lincoln.
Original Research: Full open access research for “Turbine Blade Illusion” by George Mather and Rob Lee in i-Perception. Published online May 25 2017 doi:10.1177/2041669517710031
[cbtabs][cbtab title=”MLA”]University of Lincoln “From Blue and Black Dresses to Turbine Blades: The Science of ‘Fake Fake’ Photos.” NeuroscienceNews. NeuroscienceNews, 25 May 2017.
<https://neurosciencenews.com/fake-photo-neuroscience-6768/>.[/cbtab][cbtab title=”APA”]University of Lincoln (2017, May 25). From Blue and Black Dresses to Turbine Blades: The Science of ‘Fake Fake’ Photos. NeuroscienceNew. Retrieved May 25, 2017 from https://neurosciencenews.com/fake-photo-neuroscience-6768/[/cbtab][cbtab title=”Chicago”]University of Lincoln “From Blue and Black Dresses to Turbine Blades: The Science of ‘Fake Fake’ Photos.” https://neurosciencenews.com/fake-photo-neuroscience-6768/ (accessed May 25, 2017).[/cbtab][/cbtabs]
Abstract
Turbine Blade Illusion
In January 2017, a large wind turbine blade was installed temporarily in a city square as a public artwork. At first sight, media photographs of the installation appeared to be fakes – the blade looks like it could not really be part of the scene. Close inspection of the object shows that its paradoxical visual appearance can be attributed to unconscious assumptions about object shape and light source direction.
“Turbine Blade Illusion” by George Mather and Rob Lee in i-Perception. Published online May 25 2017 doi:10.1177/2041669517710031
