Vello Accelerator AF Lens Adapters allow you to use fullframe Canon EF-mount lenses on APS-C Sony E-mount mirrorless cameras while maintaining the fullframe angle of view. By using a specialized 4 element in 4 group optical design, this adapter is able to increase a lens’ angle of view by a factor of 0.71x while simultaneously increasing the maximum aperture by one whole stop.
This allows a 50mm f/1.4 lens on an APS-C camera to maintain an angle of view close to 50mm while providing it with an f/1.0 equivalent aperture. This setup means full-frame lenses can be adapted to APS-C sensors, or full-frame cameras in APS-C crop mode, without losing the desired natural look of a full-frame system. Along with this, the adapter features electronic coupling, enabling autofocus, auto exposure, and other functions during use.