It’s not a bad example at all. It’s actually quite a good one, if you ask me.
Although it may not be everyone’s cup of tea, this type of effect is rather sought after by some and demonstrating how to achieve it using FLOSS software can only be beneficial in spreading the word that Adobe is not the only game in town.
My only critique would be the use of the eraser tool in lieu of a layer mask. A minor quibble brought on by a personal affinity for the use of layer masks. Pay it little mind.
I agree with @houz. Simulating this effect is far more complex (different size, shape and intensity of the bubbles), as you can see in this example shot with a Nikkor AIS 1.8/105mm lens af 1.8:
My main problem isn’t that it’s obviously not physically correct, but that the word “bokeh” does not mean “circles in the out of focus region” or “blurring parts of an image” or anything like that. The word has the specific meaning of describing the quality of the out of focus regions. Using it the way it is used here makes the writer look silly. It’s like saying to “add more nice” to an image. Or something like that.
@houz
You are absolutly right, but if you google “bokeh”, you will see appear a lot of images with this kind of bubbles.
As @MLC noticed, this so called Bokeh effect seems popular.
So, is there a consensus for a new name for the ‘Bokeh’ filter in G’MIC ?
Any other idea than “fake lens blur” ? (which IMHO is not what really what the filter does, and what already have a “Lens Blur” filter somewhere in G’MIC).