After selling my Nikon G Speedbooster in order to wait for the EF version, I finally got around to getting another one (the S version that works with OM-D cameras). I only had a single Nikon lens at the time so it didn't make much lens. Now with the EF version, I'm able to use nearly all of my SLR lenses. And I have to say: I'm quite pleased. Here are some snap shots from a few of my fast telephotos so far: Minolta MC 58mm f/1.2 + SB = 41mm f/.9 (82mm f/1.8 FF-equivalent): Untitled by MikeAubrey, on Flickr Canon FD 135mm f/2 + SB = 96mm f/1.4 (191mm f/2.8 FF-equivalent): Untitled by MikeAubrey, on Flickr Nikon 200mm f/2 +SB = 142mm f/1.4 (284mm f/2.8 FF-equivalent);: Untitled by MikeAubrey, on Flickr I've done little more than a bit of random shooting and I'm looking forward to getting out and doing more than snap shots. Still, I'm extremely pleased. The Nikon was never really useable on μ43 and now it looks pretty nice, though still not up to the level of quality on my A7. I'm especially happy with the Canon FD 135mm f/2. It looks awesome wide open (though focusing is hard). For those wondering...all my FD lenses were converted to EF mount back when I had my 5d, that's how I'm using them now on the EF speedbooster. The Minolta looks excellent, too. Definitely less CA & spherical aberration than it has on a regular adapter. The only downside is that with a lens like that, that's already super fast, the would-be shutter speed gain between f/1.2 and f/.9 is lost on a digital sensor because of pixel shading.