Oleg Zabluda's blog
Sunday, September 11, 2016
 
Coloured dots
Coloured dots
"""
I’ve noticed that when an object is seen from a distance in daylight, the colours appear changed. For example when I observed my wife walk round a lake in Switzerland, her pink top looked white and her blue trousers looked pink from 600 metres or more away. Do surfaces need to be sufficiently large in our field of view for us to perceive their colours correctly?

In the centre of your visual field there Is a small area that is effectively blue-blind. This “foveal tritanopia" means that objects with colours that differ onlv in how much blue they contain become indistinguishable when they are very small about the size of a tennis ball viewed from the other end of the court. So white and yellow will look identical, as will red and magenta, or blue and black.

This phenomenon has been known empirically for a long time. Naval signalling flags are designed so they cannot be confused even when viewed at a distance where this effect could manifest itself. Similarly, heraldic rules forbid a yellow emblem on a white background or vice versa, or blue on black, and so forth.

Roger Carpenter Professor of Oculomotor Physiology University of Cambridge, UK
"""
http://www.sciencedirect.com/science/article/pii/S0262407916315731

Labels:


- posted by Oleg Zabluda @ 6:40 PM | permalink | | | technorati | bloglines | feedster
| |

Home

Powered by Blogger