Patent: Cine 12-32 t/3.5 & 15.5-47 t/2.8 Lenses

A patent for two cinema lens optical formulas has been made public. Both formulas are for wide angle lenses, one is a 12-32mm t/3.5 and the other a 15.5-47mm t/2.8. NAB 2015 is just over a month away and we do expect at least one cinema lens announcement from Canon.

Full patent specs are after the break.

Patent Publication No. 2015-34858 (Google Translated)

• Published 2015.2.19
• Filing date 2013.8.8

Example 1

• Zoom ratio 2.50
• The focal length f = 12.50 18.75 31.25mm
• Fno. 3.50
• Half angle ω = 51.21 39.67 26.45 °
• Image height Y = 15.5mm
• Overall length of the lens 193.59
• BF 42.84

Example 2

• Zoom ratio 2.81
• Focal length 16.00 26.88 45.00
• Fno. 2.80
• Half angle of 44.18 30.05 19.06
• Image height Y = 15.5mm
• Overall length of the lens 247.38
• BF 43.27

Canon patent

• Negative positive and negative positive 4-group zoom
• Inner zoom (the second group)
• Inner focus (rear group of the first group)

Source: [Egami]

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