My main interest is in these now forgotton PRAKTICAR lenses, for collecting, for taking photos by these lenses,
and for preserving the precious Carl Zeiss Jena PB-lenses in good condition. (PB = Praktica Bayonet mount)
There are three nice points in those lenses, the first is that they have almost same colour rendition across,
the second is that the most of lenses have very short minimum focusing distance, and the third is that
they have uniformly very small distortion among my personal lens collection.