Lately I'm having fun exploring the 'classic glass' characteristics of older manual lenses. I prefer to use them on my X-E3 as these lenses perfectly match and balance with the rangefinder body style.
The Helios 44M lens is one of the most widespread manual lenses in the world. These were produced in the Soviet Union from 1958 to 1992 on a massive scale. The internal design is based on then-popular Zeiss Biotar 58mm f/2 lens. The 58mm focuslength on a APS-C sensor turns into a 87mm FOV equivalent which makes it a really nice medium tele lens. I bought this lens because of 'the swirley bokeh effect', also known as “Cat-eye” effect. This effect gives a special feeling as the background “swirls” around the center focus subject.