A rare patent for an EF-S lens optical formula has appeared in the form of a Canon EF-S 100-300mm f/4-5.6 IS. I’m quite interested in seeing how much development Canon puts into APS-C cameras and EF-S lenses in the coming years.
Patent Publication No. 2015-138178
- Published 2015.7.30
- Filing date 2014.1.23
Example 1
- Focal length 102.00 195.50 291.20mm
- F number 4.16 5.14 5.88
- Half angle of 7.63 4.00 2.69 °
- Positive and negative positive and negative four-group zoom
- Anti-vibration (part of the second group)
- Source: Egami
