Here is a new Canon patent application, as usual for RF-mount lenses. Canon patent application…
Canon Patent For 100-400mm f/3.5-5.6 STM And 55-250mm f/4-5.6 IS STM Lenses
Egami (translated) spotted a patent filed by Canon for 100-400mm f/3.5-5.6 STM and 55-250mm f/4-5.6 IS STM lenses.
- Patent Publication No. 2014-102462
- Publication date 2014.6.5
- Filing date 2012.11.22
- Example 1
- Zoom ratio 4.24
- Focal length f = 56.90-133.00-241.28mm
- Fno. 4.12-5.04-5.83
- Half angle ω = 13.50-5.86-3.24 °
- Image height 13.66mm
- 154.33-176.38-191.20mm overall length of the lens
- BF 41.21mm
- Example 5
- Zoom ratio 3.73
- Focal length f = 104.59-199.99-389.99mm
- Fno. 4.58-5.03-5.87
- Half angle ω = 11.69-6.17-3.18 °
- Image height 21.64mm
- 245.09-285.06-308.91mm overall length of the lens
- BF 68.73mm