Canon Patent for 17-55mm and 18-55mm STM Lenses (new kit lenses?)
Egami (translated) found a patent filed by Canon that appears to refer to new kit lenses: 17-55mm f/3.5-5.6 STM and 18-55mm f/3.5-5.6 STM. s you can see both lenses feature Canon’s newer STM (stepping motor) technology to drive the lens. STM is almost silent when operating, hence useful for videography.
- Patent Publication No. 2014-21258
- Publication date 2014.2.3
- Filing date 2012.7.18
- Example 2
- Zoom ratio 2.92
- Focal length f = 18.50-32.89-54.00mm
- Fno. 3.49-4.39-5.80
- Half angle ω = 36.44-22.55-14.20 °
- Image height Y = 13.66mm
- 119.77-110.06-120.23mm overall length of the lens
- BF 37.98-52.51-74.3mm
- Example 3
- Zoom ratio 3.09
- Focal length f = 17.50-32.05-54.00mm
- Fno. 3.47-4.38-5.80
- Half angle ω = 37.97-23.08-14.20 °
- Image height Y = 13.66mm
- 119.55-108.81-118.68mm overall length of the lens
- BF 36.59-51.53-73.93mm
- Canon patents
- 4-group zoom of positive and negative positive negative
- Inner folder – Kas (Group 3)
- The fourth lens unit can also be used for anti-vibration