The 45 mm monocle can be made for any SLR / DSLR or mirrorless camera.
Universal focal length.
This monocle can be used both for shooting in moderately confined spaces (urban environment, not wide streets), and for shooting landscapes on vast open spaces.

The monocle has a high level of spherical aberrations, it allows you to adjust the softness of the image within a wide range.
The image created by this monocle is identical to the 50 mm monocle. It's smaller focal length can be more convenient in some cases (primarily for APS-C cameras).