Mounted between a mirrorless camera and a SLR lens, Speed Booster® increases maximum aperture (hence its name), increases MTF and makes lens wider. Optics designed by Caldwell Photographic in the USA (patent pending).

Sony E-mount Speed Booster® Adapters are NOT fully compatible with full-frame format cameras (like Sony A1, A7 or A9 series). When Speed Booster® is used with a full-frame format camera, the camera is required to be used in "APS-C Size Capture" mode.