There is a photography textbook that says: Canon is not suitable to be a deputy factory lens. Nikon can match a factory lens, right?

The deputy factory lens takes the low-cost route, relying on the price advantage and the original factory competition. Every manufacturer's camera design is inhuman to others. Even gadgets like batteries have passwords. Although the lens has opened the source code to the vice factory, there is always something unknown. Of course, the lens of the deputy factory can be used, but it will not be better than the original one, and there will always be some matching problems.