(YV) 28mm f/2.8 Elmarit-M IV - Leica Wiki (English) https://www.l-camera-forum.com/leica-wiki.en/images/3/3a/Puts-2002-M-lenses.pdf Antique and Classic Cameras "Many believe the Type IV Elmarit to be the ultimate 28mm Elmarit for all around modern performance."