Canon files patent application for the optical systems of “14mm F1.4”, “20mm F1.8 IS”, “20mm F1.4”, and “24mm F1.4”

Canon appears to be exploring several ultra-fast full-frame primes, according to a newly surfaced patent spotted by Asobinet. The filing outlines four distinct optical formulas: –

Example 1

• Focal length: 14.42
• F-number: 1.46
• Half angle of view: 52.34
• Image height: 18.68
• Total length: 118.50
• Back focus: 14.00

Example 2 (this lens has been announced and is available at BHphoto)

• Focal length: 20.60
• F-number: 1.46
• Half angle of view: 42.54
• Image height: 18.90
• Total length: 117.50
• Back focus: 18.44

Example 3

• Focal length: 20.60
• F-number: 1.85
• Half angle of view: 42.64
• Image height: 18.97
• Total length: 98.50
• Back focus: 17.25

Example 4

• Focal length: 24.00
• F-number: 1.50
• Half angle of view: 38.29
• Image height: 18.95
• Total length: 113.00
• Back focus: 12.50

Each scheme focuses by shifting a relatively large optical group, which points to compatibility with VCM-style drive systems. Canon’s current VCM prime lineup doesn’t include anything wider than 20 mm, so a 14 mm f/1.4 based on Design A could be a logical future addition. By contrast, the rumored non-L 20 mm f/1.8 IS likely relies on a different optical approach; given the substantial moving focus group here, lenses derived from this patent would probably land at a higher price tier.