Zhong Yi Optics has announced a B4 to M4/3 2X extender. This allows you to run 2/3″ B4 broadcast lenses on any camera that has a M4/3 sized sensor, such as a Panasonic GH5 or BMPCC4K.
The Zhong Yi Optics B4 to M4/3 2X Extender uses an optical lens that doubles the focal length os the attached B4 lens to cover the M4/3 sensor size. The extender’s optical configuration consists of 8 elements in 5 groups.
What you clearly need to be aware of with a product like this is that you need to be able to externally power a 2/3″ B4 broadcast lens to use the servo functionality. It is also important to note that a lot of the older 2/3″ B4 lenses were designed for use on 3CCD sensors and they may not look particularly good on CMOS sensor cameras.
The end of the extender that attaches to the lens is made out of aluminum alloy, and the other end hat attaches to a camera is made out of stainless steel.
The extender features a tripod mount that that is compatible with the Arca-Swiss standard.
This is not the first B4 to M4/3 adapter. Other options have been available for years. Here are some of them:
You need to be aware that some adapters are a lot better than others.
Price & Availability
The Zhong Yi Optics B4 to M4/3 2X Extender retails for ¥ 99,000 (around $940 USD).