Pixco Pro Focal Reducer Speed Booster Lens Adapter for Turbo M42 mount Lens to Micro 4/3 Micro Four Thirds M43 Adapter It converts fullframe lenses into APS-C lenses. The advantage is to get the fullfame field of view onto the APS-C sensor. Increase exposure to 1 stop, and you can use faster shutter speed to shoot an image. Works fine, closely combined with the bayonet smooth, like the original lens. Full manual operation, manual focus, manual iris adjustment can be achieved with body manual exposure, aperture priority exposure, combined infinite focus. Compatible with: M42 Lens, Micro Four Thirds 4/3 Camera