Continue reading...Canon is full steam ahead as far as lens development goes, as a whole slew of optical formulas have appeared at patent offices.
First up, the RF mount.
Japan Patent Application 2019-066701
Canon RF 15-35mm f/2.8L
Focal distance 15.30mm 24.20mm 34.00mm
F number 2.91 2.91 2.91
Field angle 54.73° 41.80° 32.47°
Image height 21.64mm 21.64mm 21.64mm
Whole length of the lens 135.05mm 125.84mm 125.33mm
BF 13.00mm 22.20mm 32.26mm
Canon RF 17-70mm f/3.5-5.6
Focal distance 17.3mm 35.00mm 68.00mm
F number 3.58 4.18 5.85
Field angle 51.35° 31.72° 17.65°
Image height 21.64mm 21.6mm4 21.64mm
Whole length of the lens 142.70mm 138.53mm 143.42mm
BF 13.32mm 29.60mm 57.62mm
Japan Patent Application 2019-066654
Canon RF 15-35mm f/4L
Focal distance 15.45mm 24.00mm...