I bought a 46 mm inexpensive S&W threaded lens hood on eBay. It arrived today. I'm happy to report that it works on both my Panasonic Lumix 14 and 20 mm mFT lenses. Took a few test shots. Didn't notice any vignetting. Used with a Pen e-pl2 body. Both lenses had a B+H UV filter on them with the hood screwed on the filter.