EF70-300L has special design that prevents smart adapters properly handle its AF. Now Fringer EF-FX Pro smart adapter has overcome the problem. Meanwhile, all pdaf focus points' support is a must for high performance AF on X mount. That's also shown in the demo video.
I though EF lenses are all the same and planned for optimizing EF70-300L's AF on X mount in just one day. Finally I spend almost a week to solve the problem. This lens is equipped with a nonlinear AF motor which is definitely a nightmare for smart adapter developers. Its feature curve is like this:
Unlike smart adapters for GFX mount, e.g. my Contax645-GFX adapter and EF-GFX adapter from other manufacturers, smart adapters for X mount must support PDAF which is essential for high performance AF. That needs to calculate precisely on how to move AF motors which is very difficult when adapting EF70-300L. Now we made it!
Fringer EF-FX smart adapter products would be available soon. Visit my website for more information on all Fringer's products.
