The J-8 is based on the pre-war 5cm F2 Carl Zeiss Sonnar, and is available in Leica thread mount and in Contax/Kiev mount. The LTM version is normally limited to 1M close-focus. I removed the close-focus stop. The J-8 at its normal 1M min focus, wide-open at F2, on the EP2. At its new closest focus. The infinity stop also acts as the new close-focus stop.