比機身馬達的速度提高,再配合十字對焦點,可以一次合焦,比如拍貓,貓亂跑亂跳,沒有USM就可能抓不到最好的鏡頭,並且拍攝的成功率低很多。
Then how USM works and how the ellipse trace of particle on the surface of stator forms are analyzed.
其次,設計了實用的USM驅動電路
However, tool wear is high in USM, due to the abrasive cutting action.
但是,由於USM是磨削加工,因而*具損耗大。
A180 mm lens is getting long for portraits and the Canon EF180 mm f/3.5 L USM Macro Lens' slow focusing might have an impact here as well.
Based on the contact pattern between the stator and rotor, USM is classified as contact type and non-contact type.