Clockdoc -- That series of photos illustrates several points, particularly as this concept applies to portraits. The bokeh is much more pleasing to my eye with the longer lens at comparable apertures (for reasons Tiberius stated).
Also the 50mm lens pictures demonstrate what Elay pointed out regarding the number of diaphragm blades. Here, the points of light to the left of the mannequin show geometric shapes caused by the number of blades. Very interesting and good to know for those looking to improve bokeh in portraits.
Thanks for adding to the discussion!
