Canon Files Patent For 28-300mm and 28-135mm lens (reduced chromatic aberrations)
Next two Canon patents! As usual spotted by Japanese site Egami (translated) This time for a 28-135mm f/4-5.6 and a 28-300mm f/3.5-5.6 lens.The patent is about reducing chromatic aberrations.
- Patent Publication No. 2012-163746
- 2012.8.30 Release Date
- 2011.2.7 filing date
- Example 4
- Zoom ratio 4.67
- 56.11 – – 131.85mm f = 28.21 focal length
- Fno 4.12 -. 4.89 – 5.77
- Half angle of view ω = 37.48 – 21.09 – 9.32deg.
- Image height 21.64mm
- 242.67 – – 266.43mm 224.00 overall length of the lens
- BF 55.79 – 70.40 – 82.95mm
- 20 sheets of 14 group lens configuration
- Two two-sided aspherical
- Three low-dispersion glass
- Four Super UD glass
- 102.40mm effective diameter of the first surface
- 5-group zoom negative positive negative
- Example 5
- Zoom ratio 10.31
- 93.64 – – 307.06mm f = 29.77 focal length
- Fno 3.31 -. 4.71 – 5.85
- Half angle of view ω = 36.00 – 13.01 – 4.03deg.
- Image height 21.64mm
- 263.66 – – 304.01mm 209.34 overall length of the lens
- BF 61.72 – 89.40 – 106.84mm
- 18 sheets 12 groups lens configuration
- Three 3 aspherical surface
- Three low-dispersion glass
- 2 UD glass sheets
- 84.36mm effective diameter of the first surface
- 5-group zoom negative positive negative
- In the zoom lens of the positive lead type, reducing the chromatic aberration of magnification of the secondary
More graphs after the break
