Due to the protruding rear elements, certain EF cameras may not work with the Vazen 50mm lens. Please check below INCOMPATIBILITY list.
* any DSLR
* any RED camera
* any Z CAM camera
* the Canon EOS C100
* the Panasonic VariCam LT
* the Canon EF-EOS R Control Ring Mount Adapter
* the Canon EF-EOS R Mount Adapter
* any Metabones EF to Micro 4/3 adapter
* any adapter with built-in optics
Above only limits to the EF-mount cameras. PL-mount cameras should be alright.