Tokina were showing a Canon EF to PL mount 1.6x expander that is designed to allow you to use manual aperture Canon EF mount lenses on PL mount cameras. The expander is primarily designed for taking lenses that cover Super 35mm or Academy sized sensors and allowing them to be used on full frame sensor PL cameras.
Use Super 35mm glass on full frame bodies
The Tokina EF to PL mount expander increases the diameter of image circle by 1.6x on Super35 PL prime and zoom lenses. This allows for a greater variety of lens choices when filming with cameras like the RED Dragon that has a 46.31mm (8K) diagonal sensor.
But you could also do this…
Although it is not primarily designed for this purpose, you can also use the expander to put lenses such as the Canon CN-E primes onto a Super 35mm PL-mount camera. The downside to doing this is that your field of view will increase by 1.6x and you will lose 1.36 stops of light. For example if you used the expander with a Canon CN-E 14mm T3 lens on a Super 35mm sized PL mount camera your field of view would increase to 22.4mm and your aperture would drop to around T4.5. Despite these drawbacks it is the only way to use Canon EF mount lenses on a PL-mount camera.
The Tokina 1.6x Expander performs best when used with lenses that have a T2.0 or larger aperture and when the lens is stopped down to T2.8 or smaller.
Tokina EF to PL mount pricing and availability
The 1.6x Canon EF to PL mount expander is scheduled to ship sometime in the US summer and will retail for $1899US.