Egami spotted a new patent filed by Canon in Japan. The new patent describes various “normal” fast prime optical formulas.
Along with the Canon EF 55mm f/1.4 lens, another EF 35mm f/1.4 and other fast primes also mentioned in the patent.
See the various optical formula images below. Patent details translated via Google Machine.
Canon Patents For EF 55mm f/1.4 Prime Lens
Patent Description (Google Translated)
- Patent Publication No. 2014-123018
- Publication date 2014.7.3
- Filing date 2012.12.21
- Image height = 21.64mm
- Inner focus
| Example | Focal length | Fno. | Half angle | The overall length of the lens | BF | MOD |
|---|---|---|---|---|---|---|
| One | 49.53 | 1.45 | 23.60 | 99.46 | 38.10 | 450 |
| Two | 35.88 | 1.45 | 31.09 | 126.92 | 38.77 | 300 |
| Three | 55.42 | 1.45 | 21.33 | 100.44 | 40.24 | 450 |
| Four | 50.75 | 1.45 | 23.09 | 98.17 | 38.29 | 450 |
via EG
