Universal monocle for rangefinder cameras.
This monocle can be used both for shooting in moderately confined spaces (urban environment, not wide streets) and for shooting landscapes in open spaces.
The iris diaphragm of 10 blades creates a full circle at any value, so that the halo from the point light sources will always have a rounded shape.

The monocle has a high level of spherical aberrations, so the softness of the image can be adjusted within a wide range.
The monocle is paired with a camera rangefinder, so the process of shooting them is the same as when using rangefinder lenses.
When photographing with a rangefinder camera, the sight is through the viewfinder, not through the lens. When shooting with a monocle, this makes it easier to focus than when shooting with SLR/DSLR cameras.