I'd like to share a discovery with you. It happened by sheer coincidence: while playing around and trying different options to replace destroyed rear element of Pentacon (Meyer-Optik Gorlitz Orestor) 2.8/100mm i picked up spare Prakticar (Meyer-Optik Gorlitz Oreston derivative) 1.8/50mm rear system and luckily it went into the empty hole without any problem. Near perfect fit. Cool, but now let's test what happens with the image. The photos came out special band usable even wide open. Swirly bokeh similar to cult Biotar/Helios 1.5/85mm; front system is Sonnar type cemented elemets. Focal length somewhere between 100 and 50mm. Flange nevertheless allowed only close focusing. By modifying Sony A7 L39 adapter (inner female mount was replaced by M42) and adding 14mm macro ring i got near ideal flange that allowed infinity on Sony A7. Lens primary purpose i think would be portrait. Sorry for lack of good samples, just my 72 years old mom. Second purpose would be swirly background character, bubble bokeh, flowers genre. Surely distinctive and unique. Stepped down it gets sharp. *Front glass has coating removed thus contrast is lower with minor glow which add to the poetic effect. Lens is otherwise clean and healthy. Aperture proper. Lens label not yet on photos but will be included. Shipping Worldwide: Signed For, Priority, Tracking. EU 5-10 days, Rest 3-4 weeks. Please check my other listings .de since they are not visible .com. EU buyers: i can relist in EUR currency if desired.