On my visit today I saw a lovely scene "Apple Orchard" Clearview, Ontario
My jaw clenched a bit as if from nails on chalkboard looking at the bokeh. It has this hard outer edge which seems mechanical, as if looking through the vision of robotic aliens on a rural pasture. Why do some lenses do that? Surely no lens designer would think it is natural looking.
Can someone help us by explaining what causes it? Why is it done when other lens designs seem to have no problem being very sharp with a more Gaussian bokeh?
I have no doubt its a great looking lens with wonderful sharpness for in focus objects. To me personally it detracts on a good image like this. The simple beauty of life is distorted.
Examples added from the web (not mine, please right click for source)
Hard outer edge
Neutral, even disk
Soft outer edge, more light to the center of disk
Extreme, bokeh designed lens