Chinese lens maker Zhongyi Optics has added M42, Canon FD and Minolta MD lens adapters to its second-generation Lens Turbo lineup for Micro Four Thirds cameras. Like Metabones' Speedboosters, the adapters shorten the effective focal length, reducing the F-number by one stop and partially negating the crop factor. The 0.726x focal length reduction combines to give a net 1.45x focal length crop, rather than the 2x crop that you'd usually experience on a Micro Four Thirds camera.

These three adapters join ZY Optics' existing Lens Turbo Version II adapters for Canon EF and Nikon G lenses. Among the adapters' four optical elements is an extra-low dispersion element, and all three offer stainless steel mounts and metal bodies.

All three adapters are available directly from ZY Optics for $149 USD.