Canon’s New Patent: Canon EF 35 f/1.4L II
A new patent of Canon 35mm f/1.4 Lens has appeared. This is the second patent of the same len. There is another patent of the same lens. No doubt this is one of the most anticipated upgrade.
Patent Publication No. 2012-123155
- 2012.6.28 Release Date
- 2010.12.8 filing date
Example 1
- Focal length f = 34.73mm
- Fno. 1.45
- Half angle of 31.92 deg.
- Image height 21.64mm
- Length 128.11mm lens
- 38.48mm back focus
- An effective diameter of 52.03mm lens
- Effective diameter aperture 25.52mm
- Lens Construction 12 elements in 9 groups sheet
- 2 2 aspherical surface
- 2 UD glass sheet
Retrofocus
- And retro focus lens optical system focal length is shorter than the length of the optical system
- Increasingly asymmetric refractive power arrangement must be strengthened a negative refractive power of the front group in particular
- Coma aberration, astigmatism, spherical aberration occurs
- Order to secure a back focus must be to increase the ratio retro
What is Patent?
A lens cannot be patent, but an optical design can be patent. Not necessarily they will all end up in production line, but many patents actually have turned into a real product
A lens cannot be patent, but an optical design can be patent. Not necessarily they will all end up in production line, but many patents actually have turned into a real product
Source: EG
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