This is a modified D. Zuiko 2.8cm f3.5 lens (photo 8) from an Olympus Pen S3.5 camera (released in 1959) for Sony NEX-E mount. It is not an original Olympus Pen lens (the removed aperture blades are 5, photo 10). The lens has been disassembled, cleaned, and reassembled, so it is very clean. The shutter blades have been removed, and the shutter is always open, allowing you to select any aperture. The shutter speed dial does not rotate. It is fixed in the 1/30 position for design purposes and does not function. The aperture is adjusted from f3.5 to 22 using the ring on the front lens element (although some units have misaligned aperture positions, this one has been adjusted and fixed). Focusing is indicated on the lens barrel from 0.6m to ∞, and it has been adjusted to achieve accurate infinity focus (∞). Therefore, the focus will be accurate according to the distance scale on the focus ring. The red markings on the focus ring at 2m and 5m would normally have click stops, but this unit has been modified to eliminate them, allowing for very smooth focusing throughout the range. The focus ring rotates very smoothly (due to greasing). The Sony NEX-E mount is made of metal, and the outer circumference of the rear lens element is secured with a reinforcing ring, providing a secure fit. The rear lens surface has been painted with anti-reflective internal light-shielding paint. This lens was originally created for my own use, prioritizing improvements for shooting and ease of use (I didn't want to part with it, but the reason is in my profile). Photos taken with my NEX-7, using color STD mode at f8, without correction, are included at the end. They were intentionally shot in backlight to show the characteristics of the lens's rendering. It's a well-regarded Zuiko lens. Unlike modern lenses that prioritize sharpness, this lens is characterized by its moderately soft edge rendering. I believe this lens is designed with the Leica in mind, as designed by Mr. Kometani. I consider it a Japanese-made Leica lens (in my opinion). Although the lens being offered is for a half-frame camera, the image circle is wider than that of an f2.8 lens, so even when shooting with a full-frame α7II, the corners of the image will only be slightly cropped (photo 16). I think it's a luxurious and excellent lens. Includes a genuine filter and an aftermarket rear cap. No returns or refunds. Price is not negotiable.