Isolating my subjects from a distracting background has been a quest of mine for some time.
In the past I have mainly used longer lenses or wider apertures to create a bokeh that serves as backdrop, while still trying to give context of the location.
Lately I have been exploring the virtues and faults of lenses that were never intended for my camera, let alone a digital sensor and even less size of format (originally film).
I have been playing with lenses that were designed for 16mm film (much smaller than the sensor in my cameras).
Bell&Howell 16mm film projection lens 2" f1.6 (fixed aperture) 1/250sec
As the image circle does not fully cover my larger medium the edges of the lens render with great distortion. Most photographers would never accept that, myself included, just a few years ago.
Sharpness was absolute priority, anything else had to come second.
Times have changed: I have grown my artistic sense and I am distancing further away from razor sharp modern glass that unfortunately often lacks of character. My auto-focus lenses are gathering dust...
I have shifted from my professional days of capturing a "true" representation of reality where everything must be sharp to something that, through de-focusing fields and adding possibly motion blur, leads to different results. I want my images to create an emotion rather then a recording of a place/event.
Some lenses create a peculiar background blur when the focused subject and background are at the right distance from each other and the lens is often used wide open.
I call it swirly bokeh.
Bell&Howell 16mm film projection lens 2" f1.6 (fixed aperture) 1/1000sec
As I view now photography more art than science I gravitate towards images of a different nature; extreme sharpness has taken a back stage spot.