Piesker Picon 135 2.8:
forgotten lens maker from Berlin-West
Piesker lenses had some brandings:
PICON, ASTRA, ASTRANAR, VOSS, VOTAR
Shown example: Piesker Picon 138/2.8:
Filter size: 52 mm
Shortest focus distance: 2.5 m
Mounted at Pentacon bellow Made in GDR.
Its easy to mount the bellow at the M42 adapter!!!
Always circles are formed not only in the mid but also in the rim area.
The lens construction is not known,
might be a Triplet like Triotar 100/2.8 from Meyer?
Of course, like with all lenses,
you can use it for art work
Fotounification, thanks to Muncaski Martin
Fotounification, thanks to Peter. H. Fuerst
Its just a fun to play with 60 years old lenses:
They have a own soul, e.g. Bokeh development.