STM ?

[StanC]

A STM Lens kit comes with the EOS Rebel SL1.  What is an STM Lens kit?

StanC

[kvbarkley · Accepted solution]

A lens that uses a stepper motor to focus the lens. These are well suited to video. Though they are being supplanted by USM nano-crystal technology.

[John_B · Accepted solution]

Hello StanC! STM lenses use a "Stepper Motor" for the autofocus drive motor. This technology allows a more smooth and silent autofocus, and with compatible bodies, will provide continuous autofocus in live view and video. Unlike USM, STM lenses use focus-by-wire to enable full-time manual mode. We hope this helps! 

[kvbarkley · Accepted solution]

A lens that uses a stepper motor to focus the lens. These are well suited to video. Though they are being supplanted by USM nano-crystal technology.

[John_B · Accepted solution]

Hello StanC! STM lenses use a "Stepper Motor" for the autofocus drive motor. This technology allows a more smooth and silent autofocus, and with compatible bodies, will provide continuous autofocus in live view and video. Unlike USM, STM lenses use focus-by-wire to enable full-time manual mode. We hope this helps! 

[StanC]

Thanks to you and the other who explained what STM means.

StaC

[TTMartin · Accepted solution]

---

@StanC wrote:

A STM Lens kit comes with the EOS Rebel SL1.  What is an STM Lens kit?

StanC

---

While not specifically related to what STM means. Canon improved the image quality of each lens as they converted them to the STM focus motor. So in addition to smooth, quiet, fast and accurate focus, STM also means better image quality.