The Industar-69 28mm 1:2.8, the standard lens for Russian Chaika Half-frame cameras which I acquired earlier and was adjusted to fit the flange distance of an M39 LTM lens, has a new friend now, in the form of an Olympus Attachment Lens F=130m. The lens is a 22.5mm diameter unit that Olympus produced for attachment to the inner ring of the Pen EE half-frame camera lens.
An attachment lens is primarily used to enable macro photography without the need to use a specialized primary lens. They work on the principle of a magnifying glass, allowing a primary lens to be brought to focus closer to the subject, for close-ups or macro-orientated photography. While they do not affect exposure, close-up lenses do change both the maximum and minimum focus distances of a lens.
While there are hardly any details or further info on the Olympus Attachment Lens F=130cm on the Net currently, I am happy enough with just using the lens and attachment among my small collection of garden plants, with a flower that is in bloom and a couple of other subjects.