The Canon EF 70-300L presents a challenge of sorts for smart adapter developers. The challenge lies in the fact that the lens has a non-linear ultrasonic autofocus motor. However, Fringer managed to solve this problem and released an adapter called Fringer EF-FX Pro.
Fringer comments on the situation this way: “The EF70-300L has a special design that prevents smart adaptors from working correctly with the lens autofocus system.
In fact, I thought EF lenses were all the same and I planned to optimize the EF70-300L for the X mount in just one day. But it took me a whole week to solve that problem. This lens has a non-linear autofocus motor, which is definitely a nightmare for developers. Its functional curve looks like this:
Unlike GFX mount adapters, smart adapters for the X mount must support PDAF, which is required for high performance camera autofocus. That’s why you need to precisely calculate the AF motor movement, which is very difficult when adapting the EF70-300L. Now we’ve done it!”
It sounds like the Smart Fringer adapter is a convenient tool for photography enthusiasts who own both a Canon EF 70-300L lens and a Fujifilm X-T2 camera. However, my question is, how does this adapter affect the overall performance and image quality? Would there be any significant drawbacks or limitations when using the Canon lens on a different camera body?
Is the Smart Fringer adapter compatible with other Canon EF lenses or only specific ones like the Canon EF 70-300L?