I did not see a dedicated thread for the FD to m4/3 version of the Metabones Speedbooster (http://www.metabones.com/products/details/MB_SPFD-m43-BM1) I purchased one last week so I thought I'd kick off the thread. The only FD lens I have right now is the Canon FD 300mm f/4L, but will be getting the Canon FD 24mm f/2 soon. Metabones Speedbooster FD to m4/3 Canon FD 300mm f/4L On the O-MD E-M1 One thing to note is that even though I received the latest version of the Speedbooster (with E-M1 compatibility), I still had to remove the tripod foot to be able to mount it onto the E-M1. With the foot still attached, it was getting stuck and rubbing against the bottom of the camera. The FD 300mm f/4L is a beauty of a lens. It seems sharp wide open, both with and without the Speedbooster. Here is an image comparing center 100% crops between the Speedboosted lens, the non-Speedboosted lens with matching framing, and the non-Speedboosted matching distance. (Tripod, RAW converted with Lightroom 5.3, default sharpening, camera neutral profile) Full images Speedbooster f4 (f2.8 equiv) Speedbooster f5.6 (f4 equiv) Native f4 (match framing) Native f5.6 (match framing) Native f4 (same distance) Native f5.6 (same distance) And finally, here are some example shots (handheld, IS, most with the Speedbooster and cropped, click for full image): Non-speedbooster example (sorry for the boring subject -- no critters were out to play yet!): I also bought a FD 2x teleconverter on eBay, so when that and the 24mm f2 come, I'll try to put up some more example images.