The Speed Booster with the FD lenses upgraded my Fujifilm camera to a near full-frame system: Fujifilm X System / SLR Talk Forum: Digital Photography Review
Metabones®
Metabones Canon FD/FL Lens to L-mount Speed Booster ULTRA 0.71x - With Tripod Foot - Canon FD/FL Lens to L-mount Speed Booster ULTRA 0.71x - With Tripod Foot - Rent from $13.62/week
Fujifilm X-A1 with Metabones FD-FX Speed Booster and Canon FD 50mm/f1.8: Fujifilm X System / SLR Talk Forum: Digital Photography Review