The Volna-9 (Волна-9) is a dedicated macro lens (1:2 magnification). It's a quite well-known lens and is appreciated especially for its smooth bokeh at wide aperture. Also, the iris shape changes depending on the used aperture. The logo (C within a triangle and a circle) indicates it was produced in Lytkarino (Лытка́рино, ~30km from Moscow) at the LZOS factory (Лыткаринский завод Оптического Стекла), a KMZ satellite plant.
Aperture range: f/2.8-f/16
Minimum distance focussing: 24cm
Aperture blades: 6
Princelle lists this lens as Lz80.
I use the following dedicated ARG-file with exiftool: mcvolna950f28.txt
-EXIF:LensModel=MC Volna-9 50mm f/2.8 (M42)
This works with LR4 and NEX-5 RAW-files.