In the human fovea (where all the resolving mechanism is), there are fewer S-cones (blue sensitivity) than there are M-cones (green) and L- cones (red).
Quoting Malacara ("Color Vision and Colorimetry:Theory and Applications," ISBN 0-8194-4228-3): "[the Blue S-cones] do not contribute to contrast discrimination; thus they are not able to detect image borders." You can further find a plot of red-green versus blue-yellow contrast sensitivity by searching for "Light Vision Color" by Arne Valberg in Google books and look for Figure 4.29 (page 195): http://books.google.com/books?q=%22Light+Vision+Color%22+by+Arne+Valberg Most of the compression techniques (including how digital camera sensors are manufactured) that involves color images make use of the fact that blue has little effect on resolution. Blue cones contribute mainly to hue and chroma. 73, Chen, W7AY ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html