Читать книгу Canon EOS 90D For Dummies - King Julie Adair, Robert Correll - Страница 40

When you shop for Canon lenses, you encounter these lens specifications:

 EF and EF-S: EF stands for electro focus; the S stands for short back focus. And that simply means the rear element of the lens is closer to the sensor than with an EF lens. The good news is that your 90D works with both of these Canon lens types.

 IS: Indicates that the lens offers image stabilization.

 STM: Refers to stepping motor technology, an autofocusing system that’s designed to provide smoother, quieter autofocusing.

 USM: Refers to the ultrasonic motor. USM is an older technology than STM, but USM lenses still offers quick, professional-quality autofocusing.

The 18–55mm kit lens is an EF-S lens with both Image Stabilization and stepping motor technology. The 18–135mm kit lens is also an EF-S lens with Image Stabilization technology. Complete lens info can also be found on the ring surrounding the front element of the lens.